Super Boiler: First Generation, Ultra-High Efficiency Firetube Boiler

Energy Technology Data Exchange (ETDEWEB)

None

2006-06-01

This factsheet describes a research project whose goal is to develop and demonstrate a first-generation ultra-high-efficiency, ultra-low emissions, compact gas-fired package boiler (Super Boiler), and formulate a long-range RD&D plan for advanced boiler technology out to the year 2020.

CFD Modelling of Biomass Combustion in Small-Scale Boilers. Final Report

Energy Technology Data Exchange (ETDEWEB)

Xue-Song Bai; Griselin, Niklas; Klason, Torbern; Nilsson, Johan [Lund Inst. of Tech. (Sweden). Dept. of Heat and Power Engineering

2002-10-01

This project deals with CFD modeling of combustion of wood in fixed bed boilers. A flamelet model for the interaction between turbulence and chemical reactions is developed and applied to study small-scale boiler. The flamelet chemistry employs 43 reactive species and 174 elementary reactions. It gives detailed distributions of important species such as CO and NO{sub x} in the flow field and flue gas. Simulation of a small-scale wood fired boiler measured at SP Boraas (50 KW) shows that the current flamelet model yields results agreeable to the available experimental data. A detailed chemical kinetic model is developed to study the bed combustion process. This model gives boundary conditions for the CFD analysis of gas phase volatile oxidation in the combustion chambers. The model combines a Functional Group submodel with a Depolymerisation, Vaporisation and Crosslinking submodel. The FG submodel simulates how functional groups decompose and form light gas species. The DVC submodell predicts depolymerisation and vaporisation of the macromolecular network and this includes bridge breaking and crosslinking processes, where the wood structure breaks down to fragments. The light fragments form tar and the heavy ones form metaplast. Two boilers firing wood log/chips are studied using the FG-DVC model, one is the SP Boraas small-scale boiler (50 KW) and the other is the Sydkraft Malmoe Vaerme AB's Flintraennan large-scale boiler (55 MW). The fix bed is assumed to be two zones, a partial equilibrium drying/devolatilisation zone and an equilibrium zone. Three typical biomass conversion modes are simulated, a lean fuel combustion mode, a near-stoichiometric combustion and a fuel rich gasification mode. Detailed chemical species and temperatures at different modes are obtained. Physical interpretation is provided. Comparison of the computational results with experimental data shows that the model can reasonably simulate the fixed bed biomass conversion process. CFD

Optimisation of Marine Boilers using Model-based Multivariable Control

DEFF Research Database (Denmark)

Solberg, Brian

Traditionally, marine boilers have been controlled using classical single loop controllers. To optimise marine boiler performance, reduce new installation time and minimise the physical dimensions of these large steel constructions, a more comprehensive and coherent control strategy is needed....... This research deals with the application of advanced control to a specific class of marine boilers combining well-known design methods for multivariable systems. This thesis presents contributions for modelling and control of the one-pass smoke tube marine boilers as well as for hybrid systems control. Much...... of the focus has been directed towards water level control which is complicated by the nature of the disturbances acting on the system as well as by low frequency sensor noise. This focus was motivated by an estimated large potential to minimise the boiler geometry by reducing water level fluctuations...

Experimental validation of a thermodynamic boiler model under steady state and dynamic conditions

International Nuclear Information System (INIS)

Carlon, Elisa; Verma, Vijay Kumar; Schwarz, Markus; Golicza, Laszlo; Prada, Alessandro; Baratieri, Marco; Haslinger, Walter; Schmidl, Christoph

2015-01-01

Highlights: • Laboratory tests on two commercially available pellet boilers. • Steady state and a dynamic load cycle tests. • Pellet boiler model calibration based on data registered in stationary operation. • Boiler model validation with reference to both stationary and dynamic operation. • Validated model suitable for coupled simulation of building and heating system. - Abstract: Nowadays dynamic building simulation is an essential tool for the design of heating systems for residential buildings. The simulation of buildings heated by biomass systems, first of all needs detailed boiler models, capable of simulating the boiler both as a stand-alone appliance and as a system component. This paper presents the calibration and validation of a boiler model by means of laboratory tests. The chosen model, i.e. TRNSYS “Type 869”, has been validated for two commercially available pellet boilers of 6 and 12 kW nominal capacities. Two test methods have been applied: the first is a steady state test at nominal load and the second is a load cycle test including stationary operation at different loads as well as transient operation. The load cycle test is representative of the boiler operation in the field and characterises the boiler’s stationary and dynamic behaviour. The model had been calibrated based on laboratory data registered during stationary operation at different loads and afterwards it was validated by simulating both the stationary and the dynamic tests. Selected parameters for the validation were the heat transfer rates to water and the water temperature profiles inside the boiler and at the boiler outlet. Modelling results showed better agreement with experimental data during stationary operation rather than during dynamic operation. Heat transfer rates to water were predicted with a maximum deviation of 10% during the stationary operation, and a maximum deviation of 30% during the dynamic load cycle. However, for both operational regimes the

Mathematical modelling of a steam boiler room to research thermal efficiency

International Nuclear Information System (INIS)

Bujak, J.

2008-01-01

This paper introduces a mathematical model of a boiler room to research its thermal efficiency. The model is regarded as an open thermodynamic system exchanging mass, energy, and heat with the atmosphere. On those grounds, the energy and energy balance were calculated. Here I show several possibilities concerning how this model may be applied. Test results of the coefficient of thermal efficiency were compared to a real object, i.e. a steam boiler room of the Provincial Hospital in Wloclawek (Poland). The tests were carried out for 18 months. The results obtained in the boiler room were used for verification of the mathematical model

Boiler tube failure prevention in fossil fired boilers

International Nuclear Information System (INIS)

Townsend, R.D.

1993-01-01

It is the common experience of power generating companies worldwide that the main causes of forced outages on power plant are those due to boiler tube failures on fossil units. The main reason for the large number of failures are the severe environmental conditions in fossil boilers as the effects of stress, temperature, temperature gradients, corrosion, erosion and vibration combine to produce degradation of the tube steel. Corrosion by oxidation, by combustion products and by impure boiler water can significantly reduce the tube wall thickness and result in failure of a tube many years before its designed service life. Errors can also occur in the design manufacturer, storage, operation, and maintenance of boiler tubing and the wrong material installed in a critical location can lead to premature failure. Altogether, experts in the US and UK, from many different disciplines, have identified seven broad categories of boiler tube failure mechanisms. 1 tab., 2 figs

Characterizing and modeling of an 88 MW grate-fired boiler burning wheat straw: Experience and lessons

DEFF Research Database (Denmark)

Yin, Chungen; Rosendahl, Lasse Aistrup; Clausen, Sønnik

2012-01-01

and availability. To better understand grate-firing of biomass and to establish a reliable but relatively simple Computational Fluid Dynamics (CFD) modeling methodology for industrial applications, biomass combustion in a number of different grate boilers has been measured and modeled. As one of the case studies......, modeling effort on an 88 MW grate-fired boiler burning wheat straw is presented in this paper. Different modeling issues and their expected impacts on CFD analysis of the kind of grate boilers are discussed. The modeling results are compared with in-flame measurements in the 88 MW boiler, which shows...... measures will be tested in a modern 500 kW grate boiler rig...

Modelling of limestone injection for SO2 capture in a coal fired utility boiler

International Nuclear Information System (INIS)

Kovacik, G.J.; Reid, K.; McDonald, M.M.; Knill, K.

1997-01-01

A computer model was developed for simulating furnace sorbent injection for SO 2 capture in a full scale utility boiler using TASCFlow TM computational fluid dynamics (CFD) software. The model makes use of a computational grid of the superheater section of a tangentially fired utility boiler. The computer simulations are three dimensional so that the temperature and residence time distribution in the boiler could be realistically represented. Results of calculations of simulated sulphur capture performance of limestone injection in a typical utility boiler operation were presented

CFD modeling of a boiler's tubes rupture

International Nuclear Information System (INIS)

Rahimi, Masoud; Khoshhal, Abbas; Shariati, Seyed Mehdi

2006-01-01

This paper reports the results of a study on the reason for tubes damage in the superheater Platen section of the 320 MW Bisotoun power plant, Iran. The boiler has three types of superheater tubes and the damage occurs in a series of elbows belongs to the long tubes. A three-dimensional modeling was performed using an in-house computational fluid dynamics (CFD) code in order to explore the reason. The code has ability of simultaneous solving of the continuity, the Reynolds-Averaged Navier-Stokes (RANS) equations and employing the turbulence, combustion and radiation models. The whole boiler including; walls, burners, air channels, three types of tubes, etc., was modeled in the real scale. The boiler was meshed into almost 2,000,000 tetrahedral control volumes and the standard k-ε turbulence model and the Rosseland radiation model were used in the model. The theoretical results showed that the inlet 18.9 MPa saturated steam becomes superheated inside the tubes and exit at a pressure of 17.8 MPa. The predicted results showed that the temperature of the steam and tube's wall in the long tubes is higher than the short and medium size tubes. In addition, the predicted steam mass flow rate in the long tube was lower than other ones. Therefore, it was concluded that the main reason for the rupture in the long tubes elbow is changing of the tube's metal microstructure due to working in a temperature higher than the design temperature. In addition, the structural fatigue tension makes the last elbow of the long tube more ready for rupture in comparison with the other places. The concluded result was validated by observations from the photomicrograph of the tube's metal samples taken from the damaged and undamaged sections

Use of Neural Networks for modeling and predicting boiler's operating performance

International Nuclear Information System (INIS)

Kljajić, Miroslav; Gvozdenac, Dušan; Vukmirović, Srdjan

2012-01-01

The need for high boiler operating performance requires the application of improved techniques for the rational use of energy. The analysis presented is guided by an effort to find possibilities for ways energy resources can be used wisely to secure a more efficient final energy supply. However, the biggest challenges are related to the variety and stochastic nature of influencing factors. The paper presents a method for modeling, assessing, and predicting the efficiency of boilers based on measured operating performance. The method utilizes a neural network approach to analyze and predict boiler efficiency and also to discover possibilities for enhancing efficiency. The analysis is based on energy surveys of 65 randomly selected boilers located at over 50 sites in the northern province of Serbia. These surveys included a representative range of industrial, public and commercial users of steam and hot water. The sample covered approximately 25% of all boilers in the province and yielded reliable and relevant results. By creating a database combined with soft computing assistance a wide range of possibilities are created for identifying and assessing factors of influence and making a critical evaluation of practices used on the supply side as a source of identified inefficiency. -- Highlights: ► We develop the model for assessing and predicting efficiency of boilers. ► The method implies the use of Artificial Neural Network approach for analysis. ► The results obtained correspond well to collected and measured data. ► Findings confirm and present good abilities of preventive or proactive approach. ► Analysis reveals and specifies opportunities for increasing efficiency of boilers.

Boiler conversions for biomass

Energy Technology Data Exchange (ETDEWEB)

Kinni, J [Tampella Power Inc., Tampere (Finland)

1997-12-31

Boiler conversions from grate- and oil-fired boilers to bubbling fluidized bed combustion have been most common in pulp and paper industry. Water treatment sludge combustion, need for additional capacity and tightened emission limits have been the driving forces for the conversion. To accomplish a boiler conversion for biofuel, the lower part of the boiler is replaced with a fluidized bed bottom and new fuel, ash and air systems are added. The Imatran Voima Rauhalahti pulverized-peat-fired boiler was converted to bubbling fluidized bed firing in 1993. In the conversion the boiler capacity was increased by 10 % to 295 MWth and NO{sub x} emissions dropped. In the Kymmene Kuusankoski boiler, the reason for conversion was the combustion of high chlorine content biosludge. The emissions have been under general European limits. During the next years, the emission limits will tighten and the boilers will be designed for most complete combustion and compounds, which can be removed from flue gases, will be taken care of after the boiler. (orig.) 3 refs.

Boiler conversions for biomass

Energy Technology Data Exchange (ETDEWEB)

Kinni, J. [Tampella Power Inc., Tampere (Finland)

1996-12-31

Boiler conversions from grate- and oil-fired boilers to bubbling fluidized bed combustion have been most common in pulp and paper industry. Water treatment sludge combustion, need for additional capacity and tightened emission limits have been the driving forces for the conversion. To accomplish a boiler conversion for biofuel, the lower part of the boiler is replaced with a fluidized bed bottom and new fuel, ash and air systems are added. The Imatran Voima Rauhalahti pulverized-peat-fired boiler was converted to bubbling fluidized bed firing in 1993. In the conversion the boiler capacity was increased by 10 % to 295 MWth and NO{sub x} emissions dropped. In the Kymmene Kuusankoski boiler, the reason for conversion was the combustion of high chlorine content biosludge. The emissions have been under general European limits. During the next years, the emission limits will tighten and the boilers will be designed for most complete combustion and compounds, which can be removed from flue gases, will be taken care of after the boiler. (orig.) 3 refs.

Boiler water regime

Science.gov (United States)

Khavanov, Pavel; Chulenyov, Anatoly

2017-10-01

Active development of autonomous heating the past 25 years has led to the widespread use of hot-water boilers of small capacity up to 2.5 MW. Rational use of the design of autonomous sources of heating boilers design features significantly improve their technical, economic and operational performance. This publication reviewed and analyzed a number of features of the design, operation and exploitation of boilers of small capacity, significantly affecting the efficiency and reliability of their application.

Modelling of thermal processes and optimization of energy-ecology characteristics of the modern boiler plants

International Nuclear Information System (INIS)

Filkoski, Risto V.

2004-01-01

The investigation accomplished in the framework of this work is concerned with the thermal processes in the furnaces of modern steam and hot-water boilers on fossil fuels. Aerodynamic and thermal conditions in the furnaces are described and models for separate processes and phenomena that occur there are presented. By using proper CFD technique, three-dimensional models of furnaces of coal-fired power boiler, hot-water boiler with circulating fluidized bed combustion and steam boiler on liquid/gaseous fuel are created. Graphical pre-processor is used for geometry creation and mesh generation of the investigated boiler plants. Mathematical model for the gas-solids mixture flow is based on Lagrange approach for the discrete phase simulations, in addition to the transport equations for the gas phase. A standard steady semi-empirical k-E model is employed for description of the turbulent flow. Coupling of velocity and pressure is achieved by the SIMPLEC method. Coal combustion is modelled as non-premixed kinetics/diffusion-limited process by the mixture fraction/probability density function approach for the reaction chemistry, with equilibrium assumption applied for description of the system chemistry. Radiation heat transfer is computed by means of the P-1 model, which is simplified variance of the P-N model, based on the expansion of the radiation intensity into an orthogonal series of spherical harmonics. Presence of discrete solid phase in the main gas stream is effectively taken into consideration through additional terms in the radiation energy transfer equation and in other model equations. Variable emissivity coefficient of the combustion products is modelled with the weighted-sum-of-grey gases-model. A model for NO x formation and reduction is included in the computations. Numerical simulations provide results concerning the boilers operation in several regimes. A methodology for optimisation of energetic-ecological characteristics of boiler plants is proposed

Characteristics modeling for supercritical circulating fluidized bed boiler working in oxy-combustion technology

Directory of Open Access Journals (Sweden)

Balicki Adrian

2014-06-01

Full Text Available Among the technologies which allow to reduce greenhouse gas emission, mainly carbon dioxide, special attention deserves the idea of ‘zeroemission’ technology based on boilers working in oxy-combustion technology. In the paper the results of analyses of the influence of changing two quantities, namely oxygen share in oxidant produced in the air separation unit, and oxygen share in oxidant supplied to the furnace chamber on the selected characteristics of a steam boiler including the degree of exhaust gas recirculation, boiler efficiency and adiabatic flame temperature, was examined. Due to the possibility of the integration of boiler model with carbon dioxide capture, separation and storage installation, the subject of the analysis was also to determine composition of the flue gas at the outlet of a moisture condensation installation. Required calculations were made using a model of a supercritical circulating fluidized bed boiler working in oxy-combustion technology, which was built in a commercial software and in-house codes.

Study on Laws, Regulations and Standards on Energy Efficiency, Energy Conserving and Emission Reduction of Industrial Boilers in EU

Science.gov (United States)

Liu, Ren; Zhao, Yuejin; Chen, Haihong; Liang, Xiuying; Yang, Ming

2017-12-01

Industrial boilers are widely applied in such fields as factory power, building heating, and people’s lives; China is the world’s largest producer and user of industrial boilers, with very high annual energy consumption; clear requirements have been put forward by China on the energy efficiency since the “11th Five-year Plan” with the hope to save energy and reduce emission by means of energy efficiency standards and regulations on the supervision and control of various special equipment. So far, the energy efficiency of industrial boilers in China has been improved significantly but there is still a gap with the EU states. This paper analyzes the policies of energy efficiency, implementation models and methods of supervision and implementation at the EU level from laws, regulations, directives as well as standards; the paper also puts forward suggestions of energy conserving and emission reduction on the improvement of energy conserving capacity of industrial boilers in China through studying the legislations and measures of the developed countries in energy conserving of boilers.

Dynamic model of a natural water circulation boiler suitable for on-line monitoring of fossil/alternative fuel plants

International Nuclear Information System (INIS)

Sedić, Almir; Katulić, Stjepko; Pavković, Danijel

2014-01-01

Highlights: • Derivation of dynamic model of a natural water circulation boiler is presented. • Model is derived by employing basic laws of conservation of mass, energy and momentum. • Thus obtained boiler model does not include empirical relationships. • Model is validated against experimental data related to an external disturbance event. • The final model is used for simulation analysis/assessment of key boiler quantities. - Abstract: The environmental protection policies and legal obligations motivate process industries to implement new low-emission and high-efficiency technologies. For the purpose of production process optimization and related control system design it is worthwhile to first build an appropriate process model. Apart from favorable execution speed, accuracy, and reliability features, the model also needs to be straightforward and only include the physical and design characteristics of the overall plant and its individual components, instead of relying on empirical relationships. To this end, this paper presents a nonlinear dynamic model of the single-drum natural-circulation steam boiler evaporator circuit, based exclusively on the fundamental physical laws of conservation of mass, energy and momentum, wherein the reliance upon empirical relationships has been entirely avoided. The presented boiler system modeling approach is based on the analysis of the physical phenomena within the boiler drum, as well as within downcomer and furnace tubes, and it also takes into account the boiler system design-specific features such as cyclone steam separators, thus facilitating the derivation of a fully-physical process model. Due to the straightforwardness of the derived process model, it should also be useful for the analysis of similar steam boiler facilities, requiring only adjustments of key operational and design parameters such as operating pressure, temperature, steam capacity and characteristics of ancillary equipment such as pumps. To

Further development of recovery boiler; Soodakattilan kehitystyoe

Energy Technology Data Exchange (ETDEWEB)

Janka, K.; Siiskonen, P.; Sundstroem, K. [Tampella Power Oy, Tampere (Finland)] [and others

1996-12-01

The global model of a recovery boiler was further developed. The aim is to be able to model the velocity, temperature and concentration fields in a boiler. At this moment the model includes submodels for: droplet drying, pyrolysis, char burning, gas burning and for droplet trajectory. The preliminary study of NO{sub x} and fly ash behaviour in a boiler was carried out. The study concerning flow field in the superheater area was carried out a 2-dimensional case in which the inflow parameters were taken from global model of a recovery boiler. Further the prediction methods of fouling in a recovery boiler were developed based on theoretical calculations of smelting behaviour of multicomponent mixtures and measurements at operating recovery boilers. (author)

Seismic model of the nuclear boiler SPX2

International Nuclear Information System (INIS)

Christodoulou, K.

1982-01-01

A model of the nuclear boiler SPX2 is proposed in this paper enabling to carry out comparative calculations on the response to seismic effects. The calculations are made in CISE and SEPTEN departments of Electricite de France [fr

Computational Modeling and Assessment Of Nanocoatings for Ultra Supercritical Boilers

Energy Technology Data Exchange (ETDEWEB)

Gandy, David W. [Electric Power Research Institute, Inc., Palo Alto, CA (United States); Shingledecker, John P. [Electric Power Research Institute, Inc., Palo Alto, CA (United States)

2011-05-11

Coal-fired power plants are a significant part of the nation's power generating capacity, currently accounting for more than 55% of the country's total electricity production. Extending the reliable lifetimes of fossil fired boiler components and reducing the maintenance costs are essential for economic operation of power plants. Corrosion and erosion are leading causes of superheater and reheater boiler tube failures leading to unscheduled costly outages. Several types of coatings and weld overlays have been used to extend the service life of boiler tubes; however, the protection afforded by such materials was limited approximately one to eight years. Power companies are more recently focused in achieving greater plant efficiency by increasing steam temperature and pressure into the advanced-ultrasupercritical (A-USC) condition with steam temperatures approaching 760°C (1400°F) and operating pressures in excess of 35MPa (5075 psig). Unfortunately, laboratory and field testing suggests that the resultant fireside environment when operating under A-USC conditions can potentially cause significant corrosion to conventional and advanced boiler materials1-2. In order to improve reliability and availability of fossil fired A-USC boilers, it is essential to develop advanced nanostructured coatings that provide excellent corrosion and erosion resistance without adversely affecting the other properties such as toughness and thermal fatigue strength of the component material.

Extended state observer based fuzzy model predictive control for ultra-supercritical boiler-turbine unit

International Nuclear Information System (INIS)

Zhang, Fan; Wu, Xiao; Shen, Jiong

2017-01-01

Highlights: • A novel ESOFMPC is proposed based on the combination of ESO and stable MPC. • The improved ESO can overcome unknown disturbances on any channel of MIMO system. • Nonlinearity and disturbance of boiler-turbine unit can be handled simultaneously. - Abstract: The regulation of ultra-supercritical (USC) boiler-turbine unit in large-scale power plants is vulnerable to various unknown disturbances, meanwhile, the internal nonlinearity makes it a challenging task for wide range load tracking. To overcome these two issues simultaneously, an extended state observer based fuzzy model predictive control is proposed for the USC boiler-turbine unit. Firstly, the fuzzy model of a 1000-MW coal-fired USC boiler-turbine unit is established through the nonlinearity analysis. Then a fuzzy stable model predictive controller is devised on the fuzzy model using output cost function for the purpose of wide range load tracking. An improved linear extended state observer, which can estimate plant behavior variations and unknown disturbances regardless of the direct feedthrough characteristic of the system, is synthesized with the predictive controller to enhance its disturbance rejection property. Closed-loop stability of the overall control system is guaranteed. Simulation results on a 1000-MW USC boiler-turbine unit model demonstrate the effectiveness of the proposed approach.

A novel modelling approach for condensing boilers based on hybrid dynamical systems

NARCIS (Netherlands)

Satyavada, H.; Baldi, S.

2016-01-01

Condensing boilers use waste heat from flue gases to pre-heat cold water entering the boiler. Flue gases are condensed into liquid form, thus recovering their latent heat of vaporization, which results in as much as 10%–12% increase in efficiency. Modeling these heat transfer phenomena is crucial to

Advanced char burnout models for the simulation of pulverized coal fired boilers

Energy Technology Data Exchange (ETDEWEB)

T. Severin; S. Wirtz; V. Scherer [Ruhr-University, Bochum (Germany). Institute of Energy Plant Technology (LEAT)

2005-07-01

The numerical simulation of coal combustion processes is widely used as an efficient means to predict burner or system behaviour. In this paper an approach to improve CFD simulations of pulverized coal fired boilers with advanced coal combustion models is presented. In simple coal combustion models, first order Arrhenius rate equations are used for devolatilization and char burnout. The accuracy of such simple models is sufficient for the basic aspects of heat release. The prediction of carbon-in-ash is one aspect of special interest in the simulation of pulverized coal fired boilers. To determine the carbon-in-ash levels in the fly ash of coal fired furnaces, the char burnout model has to be more detailed. It was tested, in how far changing operating conditions affect the carbon-in-ash prediction of the simulation. To run several test cases in a short time, a simplified cellnet model was applied. To use a cellnet model for simulations of pulverized coal fired boilers, it was coupled with a Lagrangian particle model, used in CFD simulations, too. 18 refs., 5 figs., 5 tabs.

Methodology for identifying parameters for the TRNSYS model Type 210 - wood pellet stoves and boilers

Energy Technology Data Exchange (ETDEWEB)

Persson, Tomas; Fiedler, Frank; Nordlander, Svante

2006-05-15

This report describes a method how to perform measurements on boilers and stoves and how to identify parameters from the measurements for the boiler/stove-model TRNSYS Type 210. The model can be used for detailed annual system simulations using TRNSYS. Experience from measurements on three different pellet stoves and four boilers were used to develop this methodology. Recommendations for the set up of measurements are given and the required combustion theory for the data evaluation and data preparation are given. The data evaluation showed that the uncertainties are quite large for the measured flue gas flow rate and for boilers and stoves with high fraction of energy going to the water jacket also the calculated heat rate to the room may have large uncertainties. A methodology for the parameter identification process and identified parameters for two different stoves and three boilers are given. Finally the identified models are compared with measured data showing that the model generally agreed well with measured data during both stationary and dynamic conditions.

A risk approach to the management of boiler tube thinning

International Nuclear Information System (INIS)

Noori, Soudabeh A.; Price, John W.H.

2006-01-01

A large set of industrial thickness inspection data covering four boiler units of a power station over a period of five years was made available to the authors. The measurements were made in regions of the boiler where corrosion/erosion was the major cause of failure of the boiler tubes. There were over 40,000 separately measured data points in the data and all were collected with some care and expense. In the development of maintenance strategies for equipment, this type of data is typical of the data that must be collected and assessed. This data thus represents an opportunity to evaluate the ability to generate a useful risk approach to the management of the tubing. An important example of a risk-based approach is the American Petroleum Institute (API) Risk Based Inspection ('RBI'), API 581. A variety of problems were encountered applying this to boiler tubes. The problems include irrelevant API 581 corrosion rate tables, lack of information on how to analyse inspection data, difficulty of dealing with multiple inspection categories and lack of suitable direction for programming inspection intervals

Modeling and experiments of biomass combustion in a large-scale grate boiler

DEFF Research Database (Denmark)

Yin, Chungen; Rosendahl, Lasse; Kær, Søren Knudsen

2007-01-01

is inherently more difficult due to the complexity of the solid biomass fuel bed on the grate, the turbulent reacting flow in the combustion chamber and the intensive interaction between them. This paper presents the CFD validation efforts for a modern large-scale biomass-fired grate boiler. Modeling...... and experiments are both done for the grate boiler. The comparison between them shows an overall acceptable agreement in tendency. However at some measuring ports, big discrepancies between the modeling and the experiments are observed, mainly because the modeling-based boundary conditions (BCs) could differ...

New configurations of a heat recovery absorption heat pump integrated with a natural gas boiler for boiler efficiency improvement

International Nuclear Information System (INIS)

Qu, Ming; Abdelaziz, Omar; Yin, Hongxi

2014-01-01

Highlights: • Thermal and heat transfer models of absorption heat pumps driven by exhaust gas, hot water, or natural gas. • Natural gas boiler combustion model. • Heat exchanger for condensing. • Experimental data of a hot water absorption heat pump. • Economic assessment of heat recovery absorption heat pump for improving natural gas boilers. - Abstract: Conventional natural gas-fired boilers exhaust flue gas direct to the atmosphere at 150–200 °C, which, at such temperatures, contains large amount of energy and results in relatively low thermal efficiency ranging from 70% to 80%. Although condensing boilers for recovering the heat in the flue gas have been developed over the past 40 years, their present market share is still less than 25%. The major reason for this relatively slow acceptance is the limited improvement in the thermal efficiency of condensing boilers. In the condensing boiler, the temperature of the hot water return at the range of 50–60 °C, which is used to cool the flue gas, is very close to the dew point of the water vapor in the flue gas. Therefore, the latent heat, the majority of the waste heat in the flue gas, which is contained in the water vapor, cannot be recovered. This paper presents a new approach to improve boiler thermal efficiency by integrating absorption heat pumps with natural gas boilers for waste heat recovery (HRAHP). Three configurations of HRAHPs are introduced and discussed. The three configurations are modeled in detail to illustrate the significant thermal efficiency improvement they attain. Further, for conceptual proof and validation, an existing hot water-driven absorption chiller is operated as a heat pump at operating conditions similar to one of the devised configurations. An overall system performance and economic analysis are provided for decision-making and as evidence of the potential benefits. These three configurations of HRAHP provide a pathway to achieving realistic high-efficiency natural

Mathematical modeling and experimental study of biomass combustion in a thermal 108 MW grate-fired boiler

DEFF Research Database (Denmark)

Yin, Chungen; Rosendahl, Lasse; Kær, Søren K.

2008-01-01

Grate boilers are widely used to fire biomass for heat and power production. However grate-firing systems are often reported to have relatively high un-burnout, low efficiency and high emissions, and need to be optimized and modernized. This paper presents the efforts towards a reliable baseline...... computational fluid dynamics (CFD) model for an industrial biomass-fired grate boiler, which can be used for diagnosis and optimization of the grate boiler as well as design of new grate boilers. First, based on the design conditions, a thorough sensitivity analysis is done to evaluate the relative importance...... of different factors in CFD analysis of the grate boiler. In a late stage, a two-day measuring campaign is carried out to measure the gas temperatures and gas concentrations in the boiler using a fiber optic probe connected to a Fourier transform infrared (FTIR) spectrometer. A baseline model is then defined...

Online Monitoring System of Air Distribution in Pulverized Coal-Fired Boiler Based on Numerical Modeling

Directory of Open Access Journals (Sweden)

Żymełka Piotr

2017-12-01

Full Text Available Balanced distribution of air in coal-fired boiler is one of the most important factors in the combustion process and is strongly connected to the overall system efficiency. Reliable and continuous information about combustion airflow and fuel rate is essential for achieving optimal stoichiometric ratio as well as efficient and safe operation of a boiler. Imbalances in air distribution result in reduced boiler efficiency, increased gas pollutant emission and operating problems, such as corrosion, slagging or fouling. Monitoring of air flow trends in boiler is an effective method for further analysis and can help to appoint important dependences and start optimization actions. Accurate real-time monitoring of the air distribution in boiler can bring economical, environmental and operational benefits. The paper presents a novel concept for online monitoring system of air distribution in coal-fired boiler based on real-time numerical calculations. The proposed mathematical model allows for identification of mass flow rates of secondary air to individual burners and to overfire air (OFA nozzles. Numerical models of air and flue gas system were developed using software for power plant simulation. The correctness of the developed model was verified and validated with the reference measurement values. The presented numerical model for real-time monitoring of air distribution is capable of giving continuous determination of the complete air flows based on available digital communication system (DCS data.

Online Monitoring System of Air Distribution in Pulverized Coal-Fired Boiler Based on Numerical Modeling

Science.gov (United States)

Żymełka, Piotr; Nabagło, Daniel; Janda, Tomasz; Madejski, Paweł

2017-12-01

Balanced distribution of air in coal-fired boiler is one of the most important factors in the combustion process and is strongly connected to the overall system efficiency. Reliable and continuous information about combustion airflow and fuel rate is essential for achieving optimal stoichiometric ratio as well as efficient and safe operation of a boiler. Imbalances in air distribution result in reduced boiler efficiency, increased gas pollutant emission and operating problems, such as corrosion, slagging or fouling. Monitoring of air flow trends in boiler is an effective method for further analysis and can help to appoint important dependences and start optimization actions. Accurate real-time monitoring of the air distribution in boiler can bring economical, environmental and operational benefits. The paper presents a novel concept for online monitoring system of air distribution in coal-fired boiler based on real-time numerical calculations. The proposed mathematical model allows for identification of mass flow rates of secondary air to individual burners and to overfire air (OFA) nozzles. Numerical models of air and flue gas system were developed using software for power plant simulation. The correctness of the developed model was verified and validated with the reference measurement values. The presented numerical model for real-time monitoring of air distribution is capable of giving continuous determination of the complete air flows based on available digital communication system (DCS) data.

CECIL lances Bruce's boilers

International Nuclear Information System (INIS)

Malaugh, J.; Monaghan, D.

1994-01-01

Over the past few years Ontario Hydro has become increasingly concerned about accumulations of sludge in its nuclear plant boilers, so a comprehensive sludge management programme has been instituted to combat build-up. This included developing the tele-operated robot CECIL (Consolidated Edison Combined Inspection and Lancing) equipment, originally designed for work in PWRs, for CANDU boilers. This required a significantly reconfigured robotic system as well as modifications to the boilers themselves. Work on the Bruce A reactor is described. (4 figures). (author)

Development of an Optimizing Control Concept for Fossil-Fired Boilers using a Simulation Model

DEFF Research Database (Denmark)

Mortensen, J. H.; Mølbak, T.; Commisso, M.B.

1997-01-01

of implementation and commissioning. The optimizing control system takes into account the multivariable and nonlinear characteristics of the boiler process as a gain-scheduled LQG-controller is utilized. For the purpose of facilitating the control concept development a dynamic simulation model of the boiler process......An optimizing control system for improving the load following capabilities of power plant units has been developed. The system is implemented as a complement producing additive control signals to the existing boiler control system, a concept which has various practical advantages in terms...... model when designing a new control concept are discussed....

Sootblowing optimization for improved boiler performance

Science.gov (United States)

James, John Robert; McDermott, John; Piche, Stephen; Pickard, Fred; Parikh, Neel J.

2012-12-25

A sootblowing control system that uses predictive models to bridge the gap between sootblower operation and boiler performance goals. The system uses predictive modeling and heuristics (rules) associated with different zones in a boiler to determine an optimal sequence of sootblower operations and achieve boiler performance targets. The system performs the sootblower optimization while observing any operational constraints placed on the sootblowers.

A Model for Optimization and Analysis of Energy Flexible Boiler Plants for Building Heating Purposes

Energy Technology Data Exchange (ETDEWEB)

Nielsen, J R

1996-05-01

This doctoral thesis presents a model for optimization and analysis of boiler plants. The model optimizes a boiler plant with respect to the annual total costs or with respect to energy consumption. The optimum solution is identified for a given number of energy carriers and defined characteristics of the heat production units. The number of heat production units and the capacity of units related to each energy carrier or the capacity of units related to the same energy carrier can be found. For a problem comprising large variation during a defined analysis period the model gives the operating costs and energy consumption to be used in an extended optimization. The model can be used to analyse the consequences with respect to costs and energy consumption due to capacity margins and shifts in the boundary conditions. The model is based on a search approach comprising an operational simulator. The simulator is based on a marginal cost method and dynamic programming. The simulation is performed on an hourly basis. A general boiler characteristic representation is maintained by linear energy or cost functions. The heat pump characteristics are represented by tabulated performance and efficiency as function of state and nominal aggregate capacities. The simulation procedure requires a heat load profile on an hourly basis. The problem of the presence of capacity margins in boiler plants is studied for selected cases. The single-boiler, oil-fired plant is very sensitive to the magnitude of the losses present during burner off-time. For a plant comprising two oil-fired burners, the impact of a capacity margin can be dampened by the selected capacity configuration. The present incentive, in Norway, to install an electric element boiler in an oil-fired boiler plant is analysed. 77 refs., 74 figs., 12 tabs.

Boiling process modelling peculiarities analysis of the vacuum boiler

Science.gov (United States)

Slobodina, E. N.; Mikhailov, A. G.

2017-06-01

The analysis of the low and medium powered boiler equipment development was carried out, boiler units possible development directions with the purpose of energy efficiency improvement were identified. Engineering studies for the vacuum boilers applying are represented. Vacuum boiler heat-exchange processes where boiling water is the working body are considered. Heat-exchange intensification method under boiling at the maximum heat- transfer coefficient is examined. As a result of the conducted calculation studies, heat-transfer coefficients variation curves depending on the pressure, calculated through the analytical and numerical methodologies were obtained. The conclusion about the possibility of numerical computing method application through RPI ANSYS CFX for the boiling process description in boiler vacuum volume was given.

Solar boilers 1995. Five years solar boiler campaign

International Nuclear Information System (INIS)

Houtsma, R.; Van de Water, A.; Van Zee, E.

1995-01-01

An overview is given of the activities and the results of Marketing Communication Strategy for Solar Water Heaters in the Netherlands, carried out within the framework of the 1990-1994 National Research Program Thermal Solar Energy (NOZ-th) of the Netherlands Agency for Energy and the Environment (NOVEM). Subsequently attention is paid to the sales, the manufacturers and their products, public information activities and reactions from the consumers, the marketing activities of energy distribution companies, the role of installers, local governments and the building construction industry, and market developments. 24 figs., 21 ills., 5 tabs., 18 refs., 2 appendices

MODELLING, SIMULATING AND OPTIMIZING BOILERS

DEFF Research Database (Denmark)

Sørensen, K.; Condra, T.; Houbak, Niels

2003-01-01

, and the total stress level (i.e. stresses introduced due to internal pressure plus stresses introduced due to temperature gradients) must always be kept below the allowable stress level. In this way, the increased water-/steam space that should allow for better dynamic performance, in the end causes limited...... freedom with respect to dynamic operation of the plant. By means of an objective function including as well the price of the plant as a quantification of the value of dynamic operation of the plant an optimization is carried out. The dynamic model of the boiler plant is applied to define parts...

Fouling control in biomass boilers

Energy Technology Data Exchange (ETDEWEB)

Romeo, Luis M.; Gareta, Raquel [Centro de Investigacion de Recursos y Consumos Energeticos (CIRCE), Universidad de Zaragoza, Centro Politecnico Superior, Maria de Luna, 3, 50018 Zaragoza (Spain)

2009-05-15

One of the important challenges for biomass combustion in industrial applications is the fouling tendency and how it affects to the boiler performance. The classical approach for this question is to activate sootblowing cycles with different strategies to clean the boiler (one per shift, one each six hours..). Nevertheless, it has been often reported no effect on boiler fouling or an excessive steam consumption for sootblowing. This paper illustrates the methodology and the application to select the adequate time for activating sootblowing in an industrial biomass boiler. The outcome is a control strategy developed with artificial intelligence (Neural Network and Fuzzy Logic Expert System) for optimizing the biomass boiler cleaning and maximizing heat transfer along the time. Results from an optimize sootblowing schedule show savings up to 12 GWh/year in the case-study biomass boiler. Extra steam generation produces an average increase of turbine power output of 3.5%. (author)

CFD modeling of a boiler's tubes rupture

Energy Technology Data Exchange (ETDEWEB)

Rahimi, Masoud; Khoshhal, Abbas; Shariati, Seyed Mehdi [Chemical Engineering Department, Faculty of Engineering, Razi University, Kermanshah (Iran)

2006-12-15

This paper reports the results of a study on the reason for tubes damage in the superheater Platen section of the 320MW Bisotoun power plant, Iran. The boiler has three types of superheater tubes and the damage occurs in a series of elbows belongs to the long tubes. A three-dimensional modeling was performed using an in-house computational fluid dynamics (CFD) code in order to explore the reason. The code has ability of simultaneous solving of the continuity, the Reynolds-Averaged Navier-Stokes (RANS) equations and employing the turbulence, combustion and radiation models. The whole boiler including; walls, burners, air channels, three types of tubes, etc., was modeled in the real scale. The boiler was meshed into almost 2,000,000 tetrahedral control volumes and the standard k-{epsilon} turbulence model and the Rosseland radiation model were used in the model. The theoretical results showed that the inlet 18.9MPa saturated steam becomes superheated inside the tubes and exit at a pressure of 17.8MPa. The predicted results showed that the temperature of the steam and tube's wall in the long tubes is higher than the short and medium size tubes. In addition, the predicted steam mass flow rate in the long tube was lower than other ones. Therefore, it was concluded that the main reason for the rupture in the long tubes elbow is changing of the tube's metal microstructure due to working in a temperature higher than the design temperature. In addition, the structural fatigue tension makes the last elbow of the long tube more ready for rupture in comparison with the other places. The concluded result was validated by observations from the photomicrograph of the tube's metal samples taken from the damaged and undamaged sections. (author)

BPACK -- A computer model package for boiler reburning/co-firing performance evaluations. User`s manual, Volume 1

Energy Technology Data Exchange (ETDEWEB)

Wu, K.T.; Li, B.; Payne, R.

1992-06-01

This manual presents and describes a package of computer models uniquely developed for boiler thermal performance and emissions evaluations by the Energy and Environmental Research Corporation. The model package permits boiler heat transfer, fuels combustion, and pollutant emissions predictions related to a number of practical boiler operations such as fuel-switching, fuels co-firing, and reburning NO{sub x} reductions. The models are adaptable to most boiler/combustor designs and can handle burner fuels in solid, liquid, gaseous, and slurried forms. The models are also capable of performing predictions for combustion applications involving gaseous-fuel reburning, and co-firing of solid/gas, liquid/gas, gas/gas, slurry/gas fuels. The model package is conveniently named as BPACK (Boiler Package) and consists of six computer codes, of which three of them are main computational codes and the other three are input codes. The three main codes are: (a) a two-dimensional furnace heat-transfer and combustion code: (b) a detailed chemical-kinetics code; and (c) a boiler convective passage code. This user`s manual presents the computer model package in two volumes. Volume 1 describes in detail a number of topics which are of general users` interest, including the physical and chemical basis of the models, a complete description of the model applicability, options, input/output, and the default inputs. Volume 2 contains a detailed record of the worked examples to assist users in applying the models, and to illustrate the versatility of the codes.

Characterization of Oxy-combustion Impacts in Existing Coal-fired Boilers

Energy Technology Data Exchange (ETDEWEB)

Adams, Bradley R. [Univ. of Utah, Salt Lake City, UT (United States); Fry, Andrew R. [Univ. of Utah, Salt Lake City, UT (United States); Senior, Constance L. [Univ. of Utah, Salt Lake City, UT (United States); Shim, Hong Shig [Univ. of Utah, Salt Lake City, UT (United States); Otten, Brydger Van [Univ. of Utah, Salt Lake City, UT (United States); Wendt, Jost [Univ. of Utah, Salt Lake City, UT (United States); Shaddix, Christopher [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Tree, Dale [Brigham Young Univ., Provo, UT (United States)

2010-06-01

This report summarizes Year 2 results of a research program designed to use multi-scale experimental studies and fundamental theoretical models to characterize and predict the impacts of retrofit of existing coal-fired utility boilers for oxy-combustion. Year 2 focused extensively on obtaining experimental data from the bench-scale, lab-scale and pilot-scale reactors. These data will be used to refine and validate submodels to be implemented in CFD simulations of full-scale boiler retrofits. Program tasks are on schedule for Year 3 completion. Both Year 2 milestones were completed on schedule and within budget.

Establishing an energy efficiency recommendation for commercial boilers

International Nuclear Information System (INIS)

Ware, Michelle J.

2000-01-01

To assist the federal government in meeting its energy reduction goals, President Clinton's Executive Order 12902 established the Procurement Challenge, which directed all federal agencies to purchase equipment within the top 25th percentile of efficiency. Under the direction of DOE's Federal Energy Management Program (FEMP), the Procurement Challenge's goal is to create efficiency recommendations for all energy-using products that could substantially impact the government's energy reduction goals, like commercial boilers. A typical 5,000,000 Btuh boiler, with a thermal efficiency of 83.2%, can have lifetime energy cost savings of$40,000 when compared to a boiler with a thermal efficiency of 78%. For the federal market, which makes up 2% of the boiler market, this means lifetime energy cost savings of over$25,600,000. To establish efficiency recommendations, FEMP uses standardized performance ratings for products sold in the marketplace. Currently, the boiler industry uses combustion efficiency and, sometimes, thermal efficiency performance measures when specifying a commercial boiler. For many years, the industry has used these efficiency measures interchangeably, causing confusion about boiler performance measurements, and making it difficult for FEMP to establish the top 25th percentile of efficiency. This paper will illustrate the method used to establish FEMP's recommendation for boilers. The method involved defining a correlation between thermal and combustion efficiency among boiler classifications; using the correlation to model a data set of all the boiler types available in the market; and identifying how the correlation affected the top 25th percentile analysis. The paper also will discuss the applicability of this method for evaluating other equipment for which there are limited data on performance ratings

[Emission characteristics of fine particles from grate firing boilers].

Science.gov (United States)

Wang, Shu-Xiao; Zhao, Xiu-Juan; Li, Xing-Hua; Wei, Wei; Hao, Ji-Ming

2009-04-15

Grate firing boilers are the main type of Chinese industrial boilers, which accounts for 85% of the industrial boilers and is one of the most important emission sources of primary air pollutants in China. In this study, five boilers in three cities were selected and tested to measure the emission characteristics of PM2.5, and gaseous pollutants were applied by a compact dilution sampling system, which was developed for this field study. Results showed that particles mass size distributions for the five industrial boilers presented single peak or double peak, former peaks near 0.14 microm and the later peaks after 1.0 microm; the cyclone dust remover and wet scrubber dust remover had effective removal efficiencies not only to PM2.5, but also to PM1.0; and under the condition of same control techniques, grate firing boiler with high capacity has less PM2.5 emission than the boiler with low capacity. In the PM2.5 collected from flue gases, SO4(2-) was the most abundant ion, accounted for 20%-40% of the PM2.5; and C was the most abundant element (7.5%-31.8%), followed by S (8.4%-18.7%). Carbon balance method was applied to calculate the emission factors of these pollutants. The emission factors of PM2.5, NO, and SO2 were in the range of 0.046-0.486 g x kg(-1), 1.63-2.47 g x kg(-1), 1.35-9.95 g x kg(-1) respectively. The results are useful for the emission inventory development of industrial boilers and the source analysis of PM2.5 in atmospheric environment.

The mechanical design and validation of the helical tube boilers for Hartlepool and Heysham AGR stations

International Nuclear Information System (INIS)

Skinner, V.R.

1983-01-01

The 32 helically coiled once-through boiler units at Hartlepool and Heysham represent a major advance in the technologies of boiler design, manufacture and site construction. They are particularly complex in that they incorporate integral reheaters; they employ three different tubing materials and five different structural materials, each with operating temperature limitations; and they must fit compactly into pods in the reactor pressure vessel walls. A general description of the boilers is followed by a review of external factors which influenced the mechanical design and validation programme over 15 years. Against this background selected components are discussed in detail in terms of particular loading conditions and stress analysis. (author)

Identification and MPC control of a circulation fluidized bed boiler using an LPV model

NARCIS (Netherlands)

Huang, J.; Ji, G.; Zhu, Y.; Lin, W.; Kothare, M.; Tade, M.; Vande Wouwer, A.; Smets, I.

2010-01-01

This work studies the identification and control of circulation fluidized bed (CFB) boilers. The CFB boiler under investigation shows strong nonlinearity due to big changes of steam load. A linear parameter varying (LPV) model is used to represent the process dynamics and used in control. The steam

Model-based adaptive sliding mode control of the subcritical boiler-turbine system with uncertainties.

Science.gov (United States)

Tian, Zhen; Yuan, Jingqi; Xu, Liang; Zhang, Xiang; Wang, Jingcheng

2018-05-25

As higher requirements are proposed for the load regulation and efficiency enhancement, the control performance of boiler-turbine systems has become much more important. In this paper, a novel robust control approach is proposed to improve the coordinated control performance for subcritical boiler-turbine units. To capture the key features of the boiler-turbine system, a nonlinear control-oriented model is established and validated with the history operation data of a 300 MW unit. To achieve system linearization and decoupling, an adaptive feedback linearization strategy is proposed, which could asymptotically eliminate the linearization error caused by the model uncertainties. Based on the linearized boiler-turbine system, a second-order sliding mode controller is designed with the super-twisting algorithm. Moreover, the closed-loop system is proved robustly stable with respect to uncertainties and disturbances. Simulation results are presented to illustrate the effectiveness of the proposed control scheme, which achieves excellent tracking performance, strong robustness and chattering reduction. Copyright © 2018. Published by Elsevier Ltd.

Developing Boiler Concepts as Integrated Units

DEFF Research Database (Denmark)

Sørensen, Kim; Condra, Thomas Joseph; Houbak, Niels

2004-01-01

- consisting of pressure part, burner and control system. The Technical University of Denmark, MEK - Energy Engineering Section [12] has participated in the modelling process. The project has included static and dynamic modelling of the boiler concept. For optimization of operation, verication of performance......With the objective to be able to optimize the design and operation of steam boiler concepts Aalborg Industries A/S [1] has together with Aalborg University, Institute of Energy Technology [9] carried out a development project paying special attention to the boiler concept as an integrated unit......, emissions and to obtain long time operation experiences with the boiler concept, a full scale prototype has been built and these tests have been accomplished on the prototype. By applying this integrated unit approach to the boiler concept development it has been possible to optimize the different building...

Data-Reconciliation Based Fault-Tolerant Model Predictive Control for a Biomass Boiler

Directory of Open Access Journals (Sweden)

Palash Sarkar

2017-02-01

Full Text Available This paper presents a novel, effective method to handle critical sensor faults affecting a control system devised to operate a biomass boiler. In particular, the proposed method consists of integrating a data reconciliation algorithm in a model predictive control loop, so as to annihilate the effects of faults occurring in the sensor of the flue gas oxygen concentration, by feeding the controller with the reconciled measurements. Indeed, the oxygen content in flue gas is a key variable in control of biomass boilers due its close connections with both combustion efficiency and polluting emissions. The main benefit of including the data reconciliation algorithm in the loop, as a fault tolerant component, with respect to applying standard fault tolerant methods, is that controller reconfiguration is not required anymore, since the original controller operates on the restored, reliable data. The integrated data reconciliation–model predictive control (MPC strategy has been validated by running simulations on a specific type of biomass boiler—the KPA Unicon BioGrate boiler.

IGA/SCC propagation rate measurements on alloy 600 steam generator tubing using a side stream model boiler

International Nuclear Information System (INIS)

Takamatsu, H.; Matsueda, K.; Matsunaga, T.; Kitera, T.; Arioka, K.; Tsuruta, T.; Okamoto, S.

1993-01-01

IGA/SCC crack propagation rate measurements using various types of IGA/SCC predefected ALloy 600 tubing were tested in model boilers, a side stream model boiler at Ohi Unit 1 and similar model boilers in the laboratory. Types of IGA/SCC predefects introduced from the outside of the tubing were as follows. (1) Actual IGA/SCC predefect introduced by high temperature caustic environments; (2) Longitudinal predefect by electrodischarge machining (EDM) method, and then crack tip fatigue was introduced to serve as the marker on the fractured surface (EDM slit + fatigue). IGA/SCC crack propagation rate was measured after the destructive examination by Cr concentration profile on fracture surface for (1), and observation of intergranular fractured surface propagated from the marked fatigue was employed for (2) and (3) after the model boiler tests. As for the water chemistry conditions, mainly AVT (high N 2 H 4 ) + boric acid (5-10ppm as B in SGs) treatment for both model boilers, and some of the tests for the model boiler in the laboratory employed AVT (high N 2 H 4 ) without boric acid. The results of IGA/SCC crack propagation rate measurements were compared with each other, and the three methods employed showed a good coincidence with the rate of ca. 1 x 10 -5 mm/Hr for AVT (high N 2 H 4 ) + boric acid treatment condition, in the case that crack tip boron intensity (B/O value by IMMA analysis) of more than 1 was observed

Exergetic Modelling of Oil-Fired Steam Boilers | Ohijeagbon ...

African Journals Online (AJOL)

The performance variables and potential for energy savings in oil-fired industrial steam boilers were studied. Operational parameters of steam boilers using low pour fuel oil (LPFO) and diesel were used to determine thermodynamic properties of material streams and exergetic parameters. Analysis of thermodynamic ...

Numerical modelling of a straw-fired grate boiler

DEFF Research Database (Denmark)

Kær, Søren Knudsen

2004-01-01

The paper presents a computational fluid dynamics (CFD) analysis of a 33 MW straw-fired grate boiler. Combustion on the grate plays akey-role in the analysis of these boilers and in this work a stand-alone code was used to provide inlet conditions for the CFD analysis. Modelpredictions were...... compared with available gas temperature and species concentration measurements showing good agreement. Combustionof biomass in grate-based boilers is often associated with high emission levels and relatively high amounts of unburnt carbon in the fly ash.Based on the CFD analysis, it is suggested that poor...

DBSSP - A computer program for simulation of controlled circulation boiler and natural circulation boiler start up behavior

International Nuclear Information System (INIS)

Li Bin; Chen Tingkuan; Yang Dong

2005-01-01

In this paper, a computer program, Drum Boiler Start-up Simulation Program (DBSSP), is developed for simulating the start up behavior of controlled circulation and natural circulation boilers. The mathematical model developed here is based on the first principles of mass, energy and momentum conservations. In the boiler model, heat transfer in the waterwall, the superheater, the reheater and the economizer is simulated by the distributing parameter method, while heat transfer in the drum and the downcomer is simulated by lumped parameter analysis. The program can provide detailed flow and thermodynamic characteristics of the boiler components. The development of this program is based only on design data, so it can be used for any subcritical, controlled or natural circulation boiler. The simulation results were compared with experimental measurements, and good agreements between them were found. This program is expected to be useful for predicting the characteristics and the performance of controlled circulation and natural circulation boilers during the start up process. It also can be used to optimize a start up system for minimum start up time

Low Load Model of a Once-through Boiler with Recirculation

DEFF Research Database (Denmark)

Trangbæk, Klaus

2006-01-01

A dynamic simulation model of a once-through boiler in low to medium load is developed. When the system is in low load, water from the evaporator is recirculated through a bottle. This recirculation system is included in the model, which is then shown to fit closed-loop data from a real plant...

Modeling and optimization of processes for clean and efficient pulverized coal combustion in utility boilers

Directory of Open Access Journals (Sweden)

Belošević Srđan V.

2016-01-01

Full Text Available Pulverized coal-fired power plants should provide higher efficiency of energy conversion, flexibility in terms of boiler loads and fuel characteristics and emission reduction of pollutants like nitrogen oxides. Modification of combustion process is a cost-effective technology for NOx control. For optimization of complex processes, such as turbulent reactive flow in coal-fired furnaces, mathematical modeling is regularly used. The NOx emission reduction by combustion modifications in the 350 MWe Kostolac B boiler furnace, tangentially fired by pulverized Serbian lignite, is investigated in the paper. Numerical experiments were done by an in-house developed three-dimensional differential comprehensive combustion code, with fuel- and thermal-NO formation/destruction reactions model. The code was developed to be easily used by engineering staff for process analysis in boiler units. A broad range of operating conditions was examined, such as fuel and preheated air distribution over the burners and tiers, operation mode of the burners, grinding fineness and quality of coal, boiler loads, cold air ingress, recirculation of flue gases, water-walls ash deposition and combined effect of different parameters. The predictions show that the NOx emission reduction of up to 30% can be achieved by a proper combustion organization in the case-study furnace, with the flame position control. Impact of combustion modifications on the boiler operation was evaluated by the boiler thermal calculations suggesting that the facility was to be controlled within narrow limits of operation parameters. Such a complex approach to pollutants control enables evaluating alternative solutions to achieve efficient and low emission operation of utility boiler units. [Projekat Ministarstva nauke Republike Srbije, br. TR-33018: Increase in energy and ecology efficiency of processes in pulverized coal-fired furnace and optimization of utility steam boiler air preheater by using in

Data Analytics Based Dual-Optimized Adaptive Model Predictive Control for the Power Plant Boiler

Directory of Open Access Journals (Sweden)

Zhenhao Tang

2017-01-01

Full Text Available To control the furnace temperature of a power plant boiler precisely, a dual-optimized adaptive model predictive control (DoAMPC method is designed based on the data analytics. In the proposed DoAMPC, an accurate predictive model is constructed adaptively by the hybrid algorithm of the least squares support vector machine and differential evolution method. Then, an optimization problem is constructed based on the predictive model and many constraint conditions. To control the boiler furnace temperature, the differential evolution method is utilized to decide the control variables by solving the optimization problem. The proposed method can adapt to the time-varying situation by updating the sample data. The experimental results based on practical data illustrate that the DoAMPC can control the boiler furnace temperature with errors of less than 1.5% which can meet the requirements of the real production process.

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.

Efficient boiler operations sourcebook

Energy Technology Data Exchange (ETDEWEB)

Payne, F.W. (comp.)

1985-01-01

This book emphasizes the practical aspects of industrial and commercial boiler operations. It starts with a comprehensive review of general combustion and boiler fundamentals and then deals with specific efficiency improvement methods, and the cost savings which result. The book has the following chapter headings: boiler combustion fundamentals; boiler efficiency goals; major factors controlling boiler efficiency; boiler efficiency calculations; heat loss; graphical solutions; preparation for boiler testing; boiler test procedures; efficiency-related boiler maintenance procedures; boiler tune-up; boiler operational modifications; effect of water side and gas side scale deposits; load management; auxillary equipment to increase boiler efficiency; air preheaters and economizers; other types of auxillary equipment; combustion control systems and instrumentation; boiler O/sub 2/ trim controls; should you purchase a new boiler.; financial evaluation procedures; case studies. The last chapter includes a case study of a boiler burning pulverized coal and a case study of stoker-fired coal.

Boiler plants completed in record time

International Nuclear Information System (INIS)

Anon.

2001-01-01

Bubbling fluidised bed (BFB) combustion has steadily increased its share of the boiler market in recent years, particularly in the Nordic region, where it is particularly well-suited to handling the high moisture content biofuels produced and used by the forest products industry. Foster Wheeler is the world's leading supplier of fluidised bed combustion technology. Over 200 of the more than 300 fluidised bed boilers supplied by the company are circulating fluidised bed (CFB) designs, a market in which Foster Wheeler has more than a 40% share. Foster Wheeler Energia Oy supplied the Myllykoski project at Anjalankoski with a fluidised bed boiler, auxiliary steam boilers, and flue gas scrubber systems

A bottom-up method to develop pollution abatement cost curves for coal-fired utility boilers

International Nuclear Information System (INIS)

Vijay, Samudra; DeCarolis, Joseph F.; Srivastava, Ravi K.

2010-01-01

This paper illustrates a new method to create supply curves for pollution abatement using boiler-level data that explicitly accounts for technology cost and performance. The Coal Utility Environmental Cost (CUECost) model is used to estimate retrofit costs for five different NO x control configurations on a large subset of the existing coal-fired, utility-owned boilers in the US. The resultant data are used to create technology-specific marginal abatement cost curves (MACCs) and also serve as input to an integer linear program, which minimizes system-wide control costs by finding the optimal distribution of NO x controls across the modeled boilers under an emission constraint. The result is a single optimized MACC that accounts for detailed, boiler-specific information related to NO x retrofits. Because the resultant MACCs do not take into account regional differences in air-quality standards or pre-existing NO x controls, the results should not be interpreted as a policy prescription. The general method as well as NO x -specific results presented here should be of significant value to modelers and policy analysts who must estimate the costs of pollution reduction.

The recovery boiler advisor. Combination of practical experience and advanced thermodynamic modelling

Energy Technology Data Exchange (ETDEWEB)

Backman, R. [Aabo Akademi, Turku (Finland); Eriksson, G. [LTH/RWTH (Germany); Sundstroem, K. [Tampella Power Oy, Tampere (Finland)

1996-12-31

The Aabo Advisor is a computer based program intended to provide information about the high temperature ash and fluegas chemistry in pulping spent black liquor recovery boilers of kraft pulp mills. The program can be used for predictions of a variety of furnace and flue gas phenomena, such as fireside fouling of the heat exchanger surfaces caused by the flue gas particulate matter, emissions of SO{sub 2}(g), HCl(g) and NO{sub x}(g) with the flue gas etc. The program determines the composition of the fluegas as well as the amount and composition of the two typical fly ash fractions found in recovery boiler fluegases, the condensed fly ash particles and the carry over particles. These data are used for calculating the melting behavior of the fly ash present at different locations in the boiler and this characteristic behavior is used for the fireside fouling predictions. The program may also be used for studying how different mill processes affecting the black liquor composition affects on the fireside chemistry of the recovery boiler. As input data for the calculations only a few boiler operation parameters and the composition of the black liquor is required. The calculations are based on a one-dimensional, multi-stage chemistry model where both thermodynamic equilibrium calculations and stoichiometric material balances are used. The model calculates at first the chemistry in the lower furnace and smelt after which it moves to the upper furnace and the radiative parts of the fluegas channel. As the last block the program calculates the chemistry in the convective part, the electrostatic precipitator cath and stack. The results from each block are presented in tables, key numbers and melt curves representing the fluegas or fly ash fraction present at each location

The recovery boiler advisor. Combination of practical experience and advanced thermodynamic modelling

Energy Technology Data Exchange (ETDEWEB)

Backman, R [Aabo Akademi, Turku (Finland); Eriksson, G [LTH/RWTH (Germany); Sundstroem, K [Tampella Power Oy, Tampere (Finland)

1997-12-31

The Aabo Advisor is a computer based program intended to provide information about the high temperature ash and fluegas chemistry in pulping spent black liquor recovery boilers of kraft pulp mills. The program can be used for predictions of a variety of furnace and flue gas phenomena, such as fireside fouling of the heat exchanger surfaces caused by the flue gas particulate matter, emissions of SO{sub 2}(g), HCl(g) and NO{sub x}(g) with the flue gas etc. The program determines the composition of the fluegas as well as the amount and composition of the two typical fly ash fractions found in recovery boiler fluegases, the condensed fly ash particles and the carry over particles. These data are used for calculating the melting behavior of the fly ash present at different locations in the boiler and this characteristic behavior is used for the fireside fouling predictions. The program may also be used for studying how different mill processes affecting the black liquor composition affects on the fireside chemistry of the recovery boiler. As input data for the calculations only a few boiler operation parameters and the composition of the black liquor is required. The calculations are based on a one-dimensional, multi-stage chemistry model where both thermodynamic equilibrium calculations and stoichiometric material balances are used. The model calculates at first the chemistry in the lower furnace and smelt after which it moves to the upper furnace and the radiative parts of the fluegas channel. As the last block the program calculates the chemistry in the convective part, the electrostatic precipitator cath and stack. The results from each block are presented in tables, key numbers and melt curves representing the fluegas or fly ash fraction present at each location

Oxy-Combustion Boiler Material Development

Energy Technology Data Exchange (ETDEWEB)

Gagliano, Michael; Seltzer, Andrew; Agarwal, Hans; Robertson, Archie; Wang, Lun

2012-01-31

Under U.S. Department of Energy Cooperative Agreement No. DE-NT0005262 Foster Wheeler North America Corp conducted a laboratory test program to determine the effect of oxy-combustion on boiler tube corrosion. In this program, CFD modeling was used to predict the gas compositions that will exist throughout and along the walls of air-fired and oxy-fired boilers operating with low to high sulfur coals. Test coupons of boiler tube materials were coated with deposits representative of those coals and exposed to the CFD predicted flue gases for up to 1000 hours. The tests were conducted in electric tube furnaces using oxy-combustion and air-fired flue gases synthesized from pressurized cylinders. Following exposure, the test coupons were evaluated to determine the total metal wastage experienced under air and oxy-combustions conditions and materials recommendations were made. Similar to air-fired operation, oxy-combustion corrosion rates were found to vary with the boiler material, test temperature, deposit composition, and gas composition. Despite this, comparison of air-fired and oxy-fired corrosion rates showed that oxy-firing rates were, for the most part, similar to, if not lower than those of air-firing; this finding applied to the seven furnace waterwall materials (wrought and weld overlay) and the ten superheater/reheater materials (wrought and weld overlay) that were tested. The results of the laboratory oxy-combustion tests, which are based on a maximum bulk flue gas SO2 level of 3200 ppmv (wet) / 4050 ppmv (dry), suggest that, from a corrosion standpoint, the materials used in conventional subcritical and supercritical, air-fired boilers should also be suitable for oxy-combustion retrofits. Although the laboratory test results are encouraging, they are only the first step of a material evaluation process and it is recommended that follow-on corrosion tests be conducted in coal-fired boilers operating under oxy-combustion to provide longer term (one to two year

Oxy-Combustion Boiler Material Development

Energy Technology Data Exchange (ETDEWEB)

Michael Gagliano; Andrew Seltzer; Hans Agarwal; Archie Robertson; Lun Wang

2012-01-31

Under U.S. Department of Energy Cooperative Agreement No. DE-NT0005262 Foster Wheeler North America Corp conducted a laboratory test program to determine the effect of oxy-combustion on boiler tube corrosion. In this program, CFD modeling was used to predict the gas compositions that will exist throughout and along the walls of air-fired and oxy-fired boilers operating with low to high sulfur coals. Test coupons of boiler tube materials were coated with deposits representative of those coals and exposed to the CFD predicted flue gases for up to 1000 hours. The tests were conducted in electric tube furnaces using oxy-combustion and air-fired flue gases synthesized from pressurized cylinders. Following exposure, the test coupons were evaluated to determine the total metal wastage experienced under air and oxy-combustions conditions and materials recommendations were made. Similar to air-fired operation, oxy-combustion corrosion rates were found to vary with the boiler material, test temperature, deposit composition, and gas composition. Despite this, comparison of air-fired and oxy-fired corrosion rates showed that oxy-firing rates were, for the most part, similar to, if not lower than those of air-firing; this finding applied to the seven furnace waterwall materials (wrought and weld overlay) and the ten superheater/reheater materials (wrought and weld overlay) that were tested. The results of the laboratory oxy-combustion tests, which are based on a maximum bulk flue gas SO{sub 2} level of 3200 ppmv (wet) / 4050 ppmv (dry), suggest that, from a corrosion standpoint, the materials used in conventional subcritical and supercritical, air-fired boilers should also be suitable for oxy-combustion retrofits. Although the laboratory test results are encouraging, they are only the first step of a material evaluation process and it is recommended that follow-on corrosion tests be conducted in coal-fired boilers operating under oxy-combustion to provide longer term (one to

Utilization of coal-water fuels in fire-tube boilers

International Nuclear Information System (INIS)

Sommer, T.M.; Melick, T.A.

1991-01-01

The Energy and Environmental Research Corporation (EER), in cooperation with the University of Alabama and Jim Walter Resources, has been awarded a DOE contract to retrofit an existing fire-tube boiler with a coal-water slurry firing system. Recognizing that combustion efficiency is the principle concern when firing slurry in fire-tube boilers, EER has focused the program on innovative approaches for improving carbon burnout without major modifications to the boiler. This paper reports on the program which consists of five tasks. Task 1 provides for the design and retrofit of the host boiler to fire coal-water slurry. Task 2 is a series of optimization tests that will determine the effects of adjustable parameters on boiler performance. Task 3 will perform about 1000 hours of proof-of-concept system tests. Task 4 will be a comprehensive review of the test data in order to evaluate the economics of slurry conversions. Task 5 will be the decommissioning of the test facility if required

A bottom-up method to develop pollution abatement cost curves for coal-fired utility boilers

Science.gov (United States)

This paper illustrates a new method to create supply curves for pollution abatement using boiler-level data that explicitly accounts for technology costs and performance. The Coal Utility Environmental Cost (CUECost) model is used to estimate retrofit costs for five different NO...

Pellet wood gasification boiler / Combination boiler. Market review. 7. ed.; Scheitholzvergaser-/Kombikessel. Marktuebersicht

Energy Technology Data Exchange (ETDEWEB)

Uth, Joern

2010-08-15

In the market review under consideration on pellet wood gasification boilers and combination boilers, the Federal Ministry of Food, Agriculture and Consumer Protection (Bonn, Federal Republic of Germany) report on planning and installation of wood-fired heating systems, recommendations regarding to the technical assessment of boiler systems, buffers/combination boilers, prices of pellet wood gasification boilers, data sheets of the compared pellet wood gasification boilers, pellet wood combination boilers, prices of pellet wood combination boilers, data sheets of the compared pellet wood gasification boilers, list of providers.

Market review. Pellet wood gasification boiler / combination boiler. 8. ed.; Marktuebersicht. Scheitholzvergaser-/Kombikessel

Energy Technology Data Exchange (ETDEWEB)

Uth, Joern

2012-01-15

In the market review under consideration on pellet wood gasification boilers and combination boilers, the Federal Ministry of Food, Agriculture and Consumer Protection (Bonn, Federal Republic of Germany) reports on planning and installation of wood-fired heating systems, recommendations regarding to the technical assessment of boiler systems, buffers/combination boilers, prices of pellet wood gasification boilers, data sheets of the compared pellet wood gasification boilers, pellet wood combination boilers, prices of pellet wood combination boilers, data sheets of the compared pellet wood gasification boilers, list of providers.

The behavior of ash species in suspension fired biomass boilers

DEFF Research Database (Denmark)

Jensen, Peter Arendt

While fluid bed and grate fired boilers initially was the choice of boilers used for power production from both wood and herbaceous biomass, in recent years suspension fired boilers have been increasingly used for biomass based power production. In Denmark several large pulverized fuel boilers have...... been converted from coal to biomass combustion in the last 15 years. This have included co-firing of coal and straw, up to 100% firing of wood or straw andthe use of coal ash as an additive to remedy problems with wood firing. In parallel to the commercialization of the pulverized biomass firing...... technology a long range of research studies have been conducted, to improve our understanding of the influence and behavior of biomass ash species in suspension fired boilers. The fuel ash plays a key role with respect tooptimal boiler operation and influences phenomena’s as boiler chamber deposit formation...

Modelling of thermal behaviour of iron oxide layers on boiler tubes

Science.gov (United States)

Angelo, J. D.; Bennecer, A.; Kaczmarczyk, S.; Picton, P.

2016-05-01

Slender boiler tubes are subject to localised swelling when they are expose to excessive heat. The latter is due to the formation of an oxide layer, which acts as an insulation barrier. This excessive heat can lead to microstructural changes in the material that would reduce the mechanical strength and would eventually lead to critical and catastrophic failure. Detecting such creep damage remains a formidable challenge for boiler operators. It involves a costly process of shutting down the plant, performing electromagnetic and ultrasonic non-destructive inspection, repairing or replacing damaged tubes and finally restarting the plant to resume its service. This research explores through a model developed using a finite element computer simulation platform the thermal behaviour of slender tubes under constant temperature exceeding 723 °K. Our simulation results demonstrate that hematite layers up to 15 μm thickness inside the tubes do not act as insulation. They clearly show the process of long term overheating on the outside of boiler tubes which in turn leads to initiation of flaws.

Thermomechanical finite element analysis of hot water boiler structure

Directory of Open Access Journals (Sweden)

Živković Dragoljub S.

2012-01-01

Full Text Available The paper presents an application of the Finite Elements Method for stress and strain analysis of the hot water boiler structure. The aim of the research was to investigate the influence of the boiler scale on the thermal stresses and strains of the structure of hot water boilers. Results show that maximum thermal stresses appear in the zone of the pipe carrying wall of the first reversing chamber. This indicates that the most critical part of the boiler are weld spots of the smoke pipes and pipe carrying plate, which in the case of significant scale deposits can lead to cracks in the welds and water leakage from the boiler. The nonlinear effects were taken into account by defining the bilinear isotropic hardening model for all boiler elements. Temperature dependency was defined for all relevant material properties, i. e. isotropic coefficient of thermal expansion, Young’s modulus, and isotropic thermal conductivity. The verification of the FEA model was performed by comparing the measured deformations of the hot water boiler with the simulation results. As a reference object, a Viessmann - Vitomax 200 HW boiler was used, with the installed power of 18.2 MW. CAD modeling was done within the Autodesk Inventor, and stress and strain analysis was performed in the ANSYS Software.

Chemical cleaning of UK AGR boilers

International Nuclear Information System (INIS)

Rudge, A.; Turner, P.; Ghosh, A.; Clary, W.; Tice, D.

2002-01-01

For the first time in their operational lives, UK advanced gas-cooled reactor once-through boilers have been chemically cleaned. Chemical cleaning was necessary to avoid lost output resulting from boiler pressure drops, which had been increasing for a number of years. Chemical cleaning of these boilers presents a number of unique difficulties. These include lack of access to the boilers, highly sensitised 316H superheater sections that cannot be excluded from the cleaning flow path, relatively thin boiler tube walls and an intolerance to boiler tube failure because of the role of the boilers in nuclear decay heat removal. The difficulties were overcome by implementing the clean in a staged manner, starting with an extensive materials testwork programme to select and then to substantiate the cleaning process. The selected process was based on ammoniated citric acid plus formic acid for the principal acid cleaning stage. Materials testwork was followed by an in-plant trial clean of six boiler tubes, further materials testwork and the clean of a boiler tube in a full-scale test rig. An overview is presented of the work that was carried out to demonstrate that the clean could be carried out safely, effectively and without leading to unacceptable corrosion losses. Full-scale chemical cleaning was implemented by using as much of the existing plant as possible. Careful control and monitoring was employed to ensure that the cleaning was implemented according to the specified design, thus ensuring that a safe and effective clean was carried out. Full-scale cleaning has resulted in significant boiler pressure drop recovery, even though the iron burden was relatively low and cleaning was completed in a short time. (orig.)

Numerical modelling of a straw-fired grate boiler

DEFF Research Database (Denmark)

Kær, Søren Knudsen

2004-01-01

The paper presents a computational fluid dynamics (CFD) analysis of a 33 MW straw-fired grate boiler. Combustion on the grate plays akey-role in the analysis of these boilers and in this work a stand-alone code was used to provide inlet conditions for the CFD analysis. Modelpredictions were compa...... mixing in the furnace is a key issue leading to these problems. q 2003 Elsevier Ltd. All rights reserved....

Computer simulation of the fire-tube boiler hydrodynamics

Directory of Open Access Journals (Sweden)

Khaustov Sergei A.

2015-01-01

Full Text Available Finite element method was used for simulating the hydrodynamics of fire-tube boiler with the ANSYS Fluent 12.1.4 engineering simulation software. Hydrodynamic structure and volumetric temperature distribution were calculated. The results are presented in graphical form. Complete geometric model of the fire-tube boiler based on boiler drawings was considered. Obtained results are suitable for qualitative analysis of hydrodynamics and singularities identification in fire-tube boiler water shell.

The load structure of electro boilers

International Nuclear Information System (INIS)

Feilberg, N.; Livik, K.

1995-01-01

Load measurements have been performed on 24 electro boilers with a time resolution of one hour throughout a period of one year. The boilers are used for space heating and heating of tap water in office buildings, shopping centres and apartment buildings. All boilers have tariffs with disconnection agreements. This report presents load analyses of the measurements from each boiler, and typical load profiles are calculated and presented. It also analyses how boilers are used in relation to the outdoor temperature and the power price on the spot market. All the measurements are performed in Bergen, Norway, in the period August 1993 - August 1994. Typical load profiles are shown, both annual and daily, as well as specific load parameters in addition to key figures used in calculating the total power load on the distribution network. The climate impact on energy and power load is evaluated. The report also shows examples of how the results may be applied in various special fields. 8 figs., 9 tabs

An overview of CFD modelling of small-scale fixed-bed biomass pellet boilers with preliminary results from a simplified approach

International Nuclear Information System (INIS)

Chaney, Joel; Liu Hao; Li Jinxing

2012-01-01

Highlights: ► Overview of the overall approach of modelling fixed-bed biomass boilers in CFD. ► Bed sub-models of moisture evaporation, devolatisation and char combustion reviewed. ► A method of embedding a combustion model in discrete fuel zones within the CFD is suggested. ► Includes sample of preliminary results for a 50 kW pellet boiler. ► Clear physical trends predicted. - Abstract: The increasing global energy demand and mounting pressures for CO 2 mitigation call for increased efficient utilization of biomass, particularly for heating domestic and commercial buildings. The authors of the present paper are investigating the optimization of the combustion performance and NO x emissions of a 50 kW biomass pellet boiler fabricated by a UK manufacturer. The boiler has a number of adjustable parameters including the ratio of air flow split between the primary and secondary supplies, the orientation, height, direction and number of the secondary inlets. The optimization of these parameters provides opportunities to improve both the combustion efficiency and NO x emissions. When used carefully in conjunction with experiments, Computational Fluid Dynamics (CFD) modelling is a useful tool for rapidly and at minimum cost examining the combustion performance and emissions from a boiler with multiple variable parameters. However, modelling combustion and emissions of a small-scale biomass pellet boiler is not trivial and appropriate fixed-bed models that can be coupled with the CFD code are required. This paper reviews previous approaches specifically relevant to simulating fixed-bed biomass boilers. In the first part it considers approaches to modelling the heterogeneous solid phase and coupling this with the gas phase. The essential components of the sub-models are then overviewed. Importantly, for the optimization process a model is required that has a good balance between accuracy in predicting physical trends, with low computational run time. Finally, a

HR boiler

Energy Technology Data Exchange (ETDEWEB)

1982-08-01

A number of manufacturers of central heating boilers in the Netherlands have produced high-efficiency boilers, all carrying the GIVEG-HR seal of approval (GIVEG is the manufacturers' association in the Netherlands, and HR stands for 'hoog rendement': high efficiency). Efficiences were considerably improved by reducing flue, idling and radiation losses. Control and safety, discharges of flue gases and condensate need special attention. Whether installation of a GIVEG-HR boiler is profitable in view of the cost/profit ratio, will have to be determined from case to case. N.V. Nederlandse Gasunie felt it was time to present the facts so far in a way specially aimed at the construction industry. This special edition of 'Gas and Architecture' answers a number of questions which the architect or consultant engineer might have in particular before advising on the installation of the new boiler in houses and other buildings in the interests of energy saving. A technical description of the HR boiler covers the backgrounds of its development and considers the role of the Netherlands government as regards to the introduction of the boiler.

Burnout of pulverized biomass particles in large scale boiler - Single particle model approach

Energy Technology Data Exchange (ETDEWEB)

Saastamoinen, Jaakko; Aho, Martti; Moilanen, Antero [VTT Technical Research Centre of Finland, Box 1603, 40101 Jyvaeskylae (Finland); Soerensen, Lasse Holst [ReaTech/ReAddit, Frederiksborgsveij 399, Niels Bohr, DK-4000 Roskilde (Denmark); Clausen, Soennik [Risoe National Laboratory, DK-4000 Roskilde (Denmark); Berg, Mogens [ENERGI E2 A/S, A.C. Meyers Vaenge 9, DK-2450 Copenhagen SV (Denmark)

2010-05-15

Burning of coal and biomass particles are studied and compared by measurements in an entrained flow reactor and by modelling. The results are applied to study the burning of pulverized biomass in a large scale utility boiler originally planned for coal. A simplified single particle approach, where the particle combustion model is coupled with one-dimensional equation of motion of the particle, is applied for the calculation of the burnout in the boiler. The particle size of biomass can be much larger than that of coal to reach complete burnout due to lower density and greater reactivity. The burner location and the trajectories of the particles might be optimised to maximise the residence time and burnout. (author)

BOILER MATERIALS FOR ULTRASUPERCRITICAL COAL POWER PLANTS

Energy Technology Data Exchange (ETDEWEB)

R. Viswanathan; K. Coleman; R.W. Swindeman; J. Sarver; J. Blough; W. Mohn; M. Borden; S. Goodstine; I. Perrin

2003-10-20

The principal objective of this project is to develop materials technology for use in ultrasupercritical (USC) plant boilers capable of operating with 760 C (1400 F), 35 MPa (5000 psi) steam. This project has established a government/industry consortium to undertake a five-year effort to evaluate and develop of advanced materials that allow the use of advanced steam cycles in coal-based power plants. These advanced cycles, with steam temperatures up to 760 C, will increase the efficiency of coal-fired boilers from an average of 35% efficiency (current domestic fleet) to 47% (HHV). This efficiency increase will enable coal-fired power plants to generate electricity at competitive rates (irrespective of fuel costs) while reducing CO{sub 2} and other fuel-related emissions by as much as 29%. Success in achieving these objectives will support a number of broader goals. First, from a national prospective, the program will identify advanced materials that will make it possible to maintain a cost-competitive, environmentally acceptable coal-based electric generation option. High sulfur coals will specifically benefit in this respect by having these advanced materials evaluated in high-sulfur coal firing conditions and from the significant reductions in waste generation inherent in the increased operational efficiency. Second, from a national prospective, the results of this program will enable domestic boiler manufacturers to successfully compete in world markets for building high-efficiency coal-fired power plants.

Numerical simulation of a biomass fired grate boiler

DEFF Research Database (Denmark)

Yin, Chungen; Rosendahl, Lasse; Kær, Søren Knudsen

2006-01-01

Computational fluid dynamic (CFD) analysis of the thermal flow in the combustion furnace of a biomass-fired grate boiler provides crucial insight into the boiler's performance. Quite a few factors play important roles in a general CFD analysis, such as grid, models, discretization scheme and so on....... For a grate boiler, the modeling the interaction of the fuel bed and the gas phase above the bed is also essential. Much effort can be found in literature on developing bed models whose results are introduced into CFD simulations of freeboard as inlet conditions. This paper presents a CFD analysis...... of the largest biomass-fired grate boiler in Denmark. The focus of this paper is to study how significantly an accurate bed model can affect overall CFD results, i.e., how necessarily it is to develop an accurate bed model in terms of the reliability of CFD results. The ultimate purpose of the study is to obtain...

Data-driven modeling and predictive control for boiler-turbine unit using fuzzy clustering and subspace methods.

Science.gov (United States)

Wu, Xiao; Shen, Jiong; Li, Yiguo; Lee, Kwang Y

2014-05-01

This paper develops a novel data-driven fuzzy modeling strategy and predictive controller for boiler-turbine unit using fuzzy clustering and subspace identification (SID) methods. To deal with the nonlinear behavior of boiler-turbine unit, fuzzy clustering is used to provide an appropriate division of the operation region and develop the structure of the fuzzy model. Then by combining the input data with the corresponding fuzzy membership functions, the SID method is extended to extract the local state-space model parameters. Owing to the advantages of the both methods, the resulting fuzzy model can represent the boiler-turbine unit very closely, and a fuzzy model predictive controller is designed based on this model. As an alternative approach, a direct data-driven fuzzy predictive control is also developed following the same clustering and subspace methods, where intermediate subspace matrices developed during the identification procedure are utilized directly as the predictor. Simulation results show the advantages and effectiveness of the proposed approach. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

The structure and behavior of salts in kraft recovery boilers

Energy Technology Data Exchange (ETDEWEB)

Backman, R.; Badoi, R.D.; Enestam, S. [Aabo Akademi Univ., Turku (Finland). Combustion Chemistry Research Group

1997-10-01

The melting behavior in the salt system (Na,K)(CO{sub 3},SO{sub 4},S,Cl,OH) is investigated by laboratory methods to enhance and further develop a chemical model for salt mixtures with compositions relevant for recovery boilers. The model, based on both literature data and experimental work can be used as (a) submodel in models for the over-all chemistry in recovery boilers and to estimate (b) deposit formation on heat transfer surfaces (fouling), (c) the melting properties of the fly ash, and (d) the smelt bed in recovery boilers. Experimental techniques used are thermal analysis, high temperature microscopy` and scanning electron microscopy. The model is implemented in a global calculation model which can handle both gas phases and condensed phases in the recovery boiler. The model gives a detailed description of the chemical reactions involved in the fume and dust formation in different locations of the flue gas channel in the boiler. (orig.)

Study of connected system of automatic control of load and operation efficiency of a steam boiler with extremal controller on a simulation model

Science.gov (United States)

Sabanin, V. R.; Starostin, A. A.; Repin, A. I.; Popov, A. I.

2017-02-01

The problems of operation effectiveness increase of steam boilers are considered. To maintain the optimum fuel combustion modes, it is proposed to use an extremal controller (EC) determining the value of airflow rate, at which the boiler generating the desired amount of heat will consume a minimum amount of fuel. EC sets the determined value of airflow rate to airflow rate controller (ARC). The test results of numerical simulation dynamic nonlinear model of steam boiler with the connected system of automatic control of load and combustion efficiency using EC are presented. The model is created in the Simulink modeling package of MATLAB software and can be used to optimize the combustion modes. Based on the modeling results, the conclusion was drawn about the possibility in principle of simultaneously boiler load control and optimizing by EC the combustion modes when changing the fuel combustion heat and the boiler characteristics and its operating mode. It is shown that it is possible to automatically control the operation efficiency of steam boilers when using EC without applying the standard flue gas analyzers. The article considers the numerical simulation dynamic model of steam boiler with the schemes of control of fuel consumption and airflow rate, the steam pressure and EC; the purpose of using EC in the scheme with linear controllers and the requirements to the quality of its operation; the results of operation of boiler control schemes without EC with estimation of influence of roughness of thermal mode maps on the nature of static and dynamic connection of the control units of fuel consumption and airflow rate; the phase trajectories and the diagrams of transient processes occurring in the control scheme with EC with stepped changing the fuel quality and boiler characteristics; analysis of modeling results and prospects for using EC in the control schemes of boilers.

Numerical simulation of a small-scale biomass boiler

International Nuclear Information System (INIS)

Collazo, J.; Porteiro, J.; Míguez, J.L.; Granada, E.; Gómez, M.A.

2012-01-01

Highlights: ► Simplified model for biomass combustion was developed. ► Porous zone conditions are used in the bed. ► Model is fully integrated in a commercial CFD code to simulate a small scale pellet boiler. ► Pollutant emissions are well predicted. ► Simulation provides extensive information about the behaviour of the boiler. - Abstract: This paper presents a computational fluid dynamic simulation of a domestic pellet boiler. Combustion of the solid fuel in the burner is an important issue when discussing the simulation of this type of system. A simplified method based on a thermal balance was developed in this work to introduce the effects provoked by pellet combustion in the boiler simulation. The model predictions were compared with the experimental measurements, and a good agreement was found. The results of the boiler analysis show that the position of the water tubes, the distribution of the air inlets and the air infiltrations are the key factors leading to the high emission levels present in this type of system.

MULTIPLE LINEAR REGRESSION ANALYSIS FOR PREDICTION OF BOILER LOSSES AND BOILER EFFICIENCY

OpenAIRE

Chayalakshmi C.L

2018-01-01

MULTIPLE LINEAR REGRESSION ANALYSIS FOR PREDICTION OF BOILER LOSSES AND BOILER EFFICIENCY ABSTRACT Calculation of boiler efficiency is essential if its parameters need to be controlled for either maintaining or enhancing its efficiency. But determination of boiler efficiency using conventional method is time consuming and very expensive. Hence, it is not recommended to find boiler efficiency frequently. The work presented in this paper deals with establishing the statistical mo...

Biomass boiler still best choice

International Nuclear Information System (INIS)

Wallace, Paula

2014-01-01

Full text: The City of Mount Gambier upgraded its boiler in September after analysis showed that biomass was still the optimal energy option. The Mount Gambier Aquatic Centre was built by the local city council in the 1980s as an outdoor pool facility for the public. The complex has three pools — an Olympic-sized, toddler and a learner pool — for a total volume of 1.38ML (including balance tanks). The large pool is heated to 27-28°C, the smaller one 30-32°C. From the very beginning, the pool water was heated by a biomass boiler, and via two heat exchangers whose combined capacity is 520 kW. The original biomass boiler ran on fresh sawdust from a local timber mill. After thirty years of dedicated service the original boiler had become unreliable and difficult to operate. Replacement options were investigated and included a straight gas boiler, a combined solar hot water and gas option, and biomass boilers. The boiler only produces heat, not electricity. All options were subjected to a triple bottom line assessment, which included potential capital costs, operating costs, community and environmental benefits and costs. The project was also assessed using a tool developed by Mount Gambier City Council that considers the holistic benefits — the CHAT Tool, which stands for Comprehensive Holistic Assessment Tool. “Basically it is a survey that covers environmental, social, economic and governance factors,” the council's environmental sustainability officer, Aaron Izzard told WME. In relation to environmental considerations, the kinds of questions explored by the CHAT Tool included: Sustainable use of resources — objective is to reduce council's dependence on non-renewable resources; Greenhouse emissions — objective is to reduce council's contribution of GHG into the atmosphere; Air quality — objective is to improve local air quality. The conclusion of these analyses was that while a biomass boiler would have a higher capital cost than a straight gas

Lower price for solar boilers must improve market penetration

International Nuclear Information System (INIS)

Koevoet, J.B.J.

1999-01-01

The Dutch government aims at 1.7 PJ thermal energy for the year 2007 to be supplied by solar water heaters. For that target the number of installed solar boilers must increase seven times the number of installed solar boilers in 1998. This can be stimulated by a considerable reduction of the market price for such boilers

Boilers after 30 years. State of the art. Pt. 1. From the use of calorific value to the boiler; Brennwertkessel nach 30 Jahren. Stand der Technik. T. 1. Von der Brennwertnutzung zum Brennwertkessel

Energy Technology Data Exchange (ETDEWEB)

Kremer, Robert [Deutscher Verein des Gas- und Wasserfaches e.V. (DVGW) (Germany). Fachausschuss Trinkwasserhygiene in Gebaeuden; Selbach, Juergen

2009-01-15

The economical extent with raw materials and other materials as well as the effective utilization of materials in production processes compellingly is necessary for economy reasons in all industrial industries and handicraft industries. In the case of the consumption of thermal energy, also today still amazing possibilities of energy conservation result. Boilers with which the upper calorific value of fuels can be used are well-known for 30 years but not yet sufficiently spread. One of the calorific value pioneers had to announce insolvency in the year 2000. Today one endeavoured with modern boilers to realize the technically possible and economically necessary annual consumption index of approximately 100 % in practice.

CFD Simulation On CFBC Boiler

Directory of Open Access Journals (Sweden)

Amol S. Kinkar

2015-02-01

Full Text Available Abstract Heavy industrialization amp modernization of society demands in increasing of power cause to research amp develop new technology amp efficient utilization of existing power units. Variety of sources are available for power generation such as conventional sources like thermal hydro nuclear and renewable sources like wind tidal biomass geothermal amp solar. Out of these most common amp economical way for producing the power is by thermal power stations. Various industrial boilers plays an important role to complete the power generation cycle such as CFBC Circulating Fluidized Bed Combustion FBC Fluidized Bed Combustion AFBC Atmospheric Fluidized Bed Combustion Boiler CO Boiler RG amp WHR Boiler Waster heat recovery Boiler. This paper is intended to comprehensively give an account of knowledge related to refractory amp its failure in CFBC boiler with due effect of flue gas flow during operation on refractory by using latest technology of CAD Computer aided Design amp CAE Computer aided Engineering. By conceptual application of these technology the full scale model is able to analyze in regards the flow of flue gas amp bed material flow inside the CFBC loop via CFD Computational Fluid Dynamics software. The results obtained are helpful to understand the impact of gas amp particles on refractory in different areas amp also helped to choose suitable refractory material in different regions.

Chemical cleaning of UK AGR boilers

International Nuclear Information System (INIS)

Rudge, A.; Turner, P.; Ghosh, S.; Clary, W.; Tice, D.R.

2002-01-01

For a number of years, the waterside pressure drops across the advanced gas-cooled reactor (AGR) pod boilers have been increasing. The pressure drop increases have accelerated with time, which is the converse behaviour to that expected for rippled magnetite formation (rapid initial increase slowing down with time). Nonetheless, magnetite deposition remains the most likely cause for the increasing boiler resistances. A number of potential countermeasures have been considered in response to the boiler pressure drop increases. However, there was no detectable reduction in the rate of pressure drop increase. Chemical cleaning was therefore considered and a project to substantiate and then implement chemical cleaning was initiated. (authors)

Multi-objective Optimization of Coal-fired Boiler Combustion Based on NSGA-II

OpenAIRE

Tingfang Yu; Hongzhen Zhu; Chunhua Peng

2013-01-01

NOx emission characteristics and overall heat loss model for a 300MW coal-fired boiler were established by Back Propagation (BP) neural network, by which the the functional relationship between outputs (NOx emissions & overall heat loss of the boiler) and inputs (operational parameters of the boiler) of a coal-fired boiler can be predicted. A number of field test data from a full-scale operating 300MWe boiler were used to train and verify the BP model. The NOx emissions & heat loss pr...

A theoretical approach for energy saving in industrial steam boilers

International Nuclear Information System (INIS)

Sabry, T.I.; Mohamed, N.H.; Elghonimy, A.M.

1993-01-01

Optimization of the performance characteristics of such a steam boiler has been analyzed theoretically. Suitable thermodynamic relations have been utilized here to construct a computer model that would carry out the boiler performance characteristics at different operating parameters (e.g.; amount of excess air, fuel type, rate of blowdown preheating of combustion air and flow gases temperature). The results demonstrate that this computer model is to be used successfully in selecting the different operating parameters of the steam boiler at variant loads considering the best economical operation. Besides, this model can be used to investigate the sensitivity of the performance characteristics to the deviation of the boiler operating parameters from their optimum values. It was found also that changing the operating parameters beside the type of fuel in a boiler affects its performance characteristics. 3 figs

Efficiency assessment of bi-radiated screens and improved convective set of tubes during the modernization of PTVM-100 tower hot-water boiler based on controlled all-mode mathematic models of boilers on Boiler Designer software

Science.gov (United States)

Orumbayev, R. K.; Kibarin, A. A.; Khodanova, T. V.; Korobkov, M. S.

2018-03-01

This work contains analysis of technical values of tower hot-water boiler PTVM-100 when operating on gas and oil residual. After the test it became clear that due to the construction deficiency during the combustion of oil residual, it is not possible to provide long-term production of heat. There is also given a short review on modernization of PTVM-100 hot-water boilers. With the help of calculations based on controlled all-mode mathematic modules of hot-water boilers in BOILER DESIGNER software, it was shown that boiler modernization by use of bi-radiated screens and new convective set of tubes allows decreasing sufficiently the temperature of combustor output gases and increase reliability of boiler operation. Constructive changes of boiler unit suggested by authors of this work, along with increase of boiler’s operation reliability also allow to improve it’s heat production rates and efficiency rate up to 90,5% when operating on fuel oil and outdoor installation option.

Dynamic simulation of a circulating fluidized bed boiler system part II: Simulation of a boiler system operating in a power plant

International Nuclear Information System (INIS)

Kim, Seong Il; Choi, Sang Min; Yang, Jong In

2016-01-01

A case of dynamic performance simulation model of a CFB boiler is presented in this study. The dynamic system of a CFB boiler in an operating power plant and the transient behavior of sub-models is described in the accompanying paper, Part I. The current paper, Part II, describes the model extension for the CFB boiler system in a power plant. The open loop model in Paper I was expanded by applying a set of PID (Proportional-integral-differential) control loops. In the control loop, pressure, temperature, mass flow rate of the main steam, the drum water level and the oxygen level at the stack were controlled. Dynamic performance was simulated to check the response of the closed control loop. Finally, performance of the total boiler system for a range of operation load of the power plant was simulated, where the parameters were calculated and control variables were maintained at the set values by PID control. Dynamic performance of a boiler at a selected load variation case was simulated and compared with actual measurements and their transient response characteristics were discussed. The simulation can also directly produce useful operation parameters, which are not measurable, but could be used for engineering evaluation

Dynamic simulation of a circulating fluidized bed boiler system part II: Simulation of a boiler system operating in a power plant

Energy Technology Data Exchange (ETDEWEB)

Kim, Seong Il; Choi, Sang Min; Yang, Jong In [Dept. of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon(Korea, Republic of)

2016-12-15

A case of dynamic performance simulation model of a CFB boiler is presented in this study. The dynamic system of a CFB boiler in an operating power plant and the transient behavior of sub-models is described in the accompanying paper, Part I. The current paper, Part II, describes the model extension for the CFB boiler system in a power plant. The open loop model in Paper I was expanded by applying a set of PID (Proportional-integral-differential) control loops. In the control loop, pressure, temperature, mass flow rate of the main steam, the drum water level and the oxygen level at the stack were controlled. Dynamic performance was simulated to check the response of the closed control loop. Finally, performance of the total boiler system for a range of operation load of the power plant was simulated, where the parameters were calculated and control variables were maintained at the set values by PID control. Dynamic performance of a boiler at a selected load variation case was simulated and compared with actual measurements and their transient response characteristics were discussed. The simulation can also directly produce useful operation parameters, which are not measurable, but could be used for engineering evaluation.

Advanced modelling and testing of a 13 MWth waste wood-fired grate boiler with recycled flue gas

DEFF Research Database (Denmark)

Rajh, Boštjan; Yin, Chungen; Samec, Niko

2016-01-01

as an innovative attempt to improve the boiler performance, a refined weighted-sum-of-grey-gases-model of greater accuracy is developed to better address the impacts of the elevated CO2 and H2O vapour concentrations on radiative heat transfer in the boiler. The impacts of full buoyancy on the turbulent flow...

Condensing boiler applications in the process industry

International Nuclear Information System (INIS)

Chen, Qun; Finney, Karen; Li, Hanning; Zhang, Xiaohui; Zhou, Jue; Sharifi, Vida; Swithenbank, Jim

2012-01-01

Major challenging issues such as climate change, energy prices and fuel security have focussed the attention of process industries on their energy efficiency and opportunities for improvement. The main objective of this research study was to investigate technologies needed to exploit the large amount of low grade heat available from a flue gas condensing system through industrial condensing boilers. The technology and application of industrial condensing boilers in various heating systems were extensively reviewed. As the condensers require site-specific engineering design, a case study was carried out to investigate the feasibility (technically and economically) of applying condensing boilers in a large scale district heating system (40 MW). The study showed that by recovering the latent heat of water vapour in the flue gas through condensing boilers, the whole heating system could achieve significantly higher efficiency levels than conventional boilers. In addition to waste heat recovery, condensing boilers can also be optimised for emission abatement, especially for particle removal. Two technical barriers for the condensing boiler application are corrosion and return water temperatures. Highly corrosion-resistant material is required for condensing boiler manufacture. The thermal design of a 'case study' single pass shell-and-tube condensing heat exchanger/condenser showed that a considerable amount of thermal resistance was on the shell-side. Based on the case study calculations, approximately 4900 m 2 of total heat transfer area was required, if stainless steel was used as a construction material. If the heat transfer area was made of carbon steel, then polypropylene could be used as the corrosion-resistant coating material outside the tubes. The addition of polypropylene coating increased the tube wall thermal resistance, hence the required heat transfer area was approximately 5800 m 2 . Net Present Value (NPV) calculations showed that the choice of a carbon

Behavioral study solar boilers 1994. Summary. Part 2 (households)

International Nuclear Information System (INIS)

Visser, J.M.

1995-04-01

The aim of the Dutch national solar boiler campaign of NOVEM and Holland Solar is to realize the installation of 300,000 solar boilers in the Netherlands in the year 2010. In 1995 10,000 boilers were installed. More knowledge of the decision making process and the backgrounds and motives of (potential) buyers is required. From September 1994 to March 1995 a survey has been carried out of the decision making processes in households and housing corporations. The most important results, conclusions and recommendations of the survey are summarized in this report. The parameters that can influence the decision whether to purchase a solar boiler or not are knowledge about the solar boiler, the attitude towards the solar boiler and towards the use of energy and the environment, risk perception, social aspects, information retrieval behavior, constraints, and socio-economic aspects. 44 tabs

Analysis of a waste-heat boiler by CFD simulation

Energy Technology Data Exchange (ETDEWEB)

Yang, Yongziang; Jokilaakso, A. [Helsinki Univ. of Technology, Otaniemi (Finland)

1996-12-31

Waste-heat boilers play important roles in the continuous operation of a smelter and in the conservation of energy. However, the fluid flow and heat transfer behaviour has not been well studied, concerning the boiler performance and design. This presentation describes simulated gas flow and heat transfer of a waste-heat boiler in the Outokumpu copper flash smelting process. The governing transport equations for the conservation of mass, momentum and enthalpy were solved with a commercial CFD-code PHOENICS. The standard k-{epsilon} turbulence model and a composite-flux radiation model were used in the computations. The computational results show that the flow is strongly recirculating and distinctly three-dimensional in most part of the boiler, particularly in the radiation section. The predicted flow pattern and temperature distribution were in a good agreement with laboratory models and industrial measurements. The results provide detailed information of flow pattern, the temperature distribution and gas cooling efficiency. The CFD proved to be a useful tool in analysing the boiler operation. (author)

Analysis of a waste-heat boiler by CFD simulation

Energy Technology Data Exchange (ETDEWEB)

Yang, Yongziang; Jokilaakso, A [Helsinki Univ. of Technology, Otaniemi (Finland)

1997-12-31

Waste-heat boilers play important roles in the continuous operation of a smelter and in the conservation of energy. However, the fluid flow and heat transfer behaviour has not been well studied, concerning the boiler performance and design. This presentation describes simulated gas flow and heat transfer of a waste-heat boiler in the Outokumpu copper flash smelting process. The governing transport equations for the conservation of mass, momentum and enthalpy were solved with a commercial CFD-code PHOENICS. The standard k-{epsilon} turbulence model and a composite-flux radiation model were used in the computations. The computational results show that the flow is strongly recirculating and distinctly three-dimensional in most part of the boiler, particularly in the radiation section. The predicted flow pattern and temperature distribution were in a good agreement with laboratory models and industrial measurements. The results provide detailed information of flow pattern, the temperature distribution and gas cooling efficiency. The CFD proved to be a useful tool in analysing the boiler operation. (author)

Electric Boiler and Heat Pump Thermo-Electrical Models for Demand Side Management Analysis in Low Voltage Grids

DEFF Research Database (Denmark)

Diaz de Cerio Mendaza, Iker; Bak-Jensen, Birgitte; Chen, Zhe

2013-01-01

The last fifteen years many European countries have integrated large percentage of renewable energy on their electricity generation mix. In Denmark the 21.3% of the electricity consumed nowadays is produced by the wind, and it has planned to be the 50% by 2025. In order to front future challenges...... on the power system control and operation, created by this unstable way of generation, Demand Side Management turns to be a promising solution. The storage capacity from thermo-electric units, like electric boilers and heat pumps, allows operating them with certain freedom. Hence they can be employed under...... certain coordination, to actively respond to the power system fluctuations. The following paper presents two simple thermo-electrical models of an electrical boiler and an air-source CO2 heat pump system. The purpose is using them in low voltage grids analysis to assess their capacity and flexibility...

Numerical investigation of ash deposition in straw-fired boilers

DEFF Research Database (Denmark)

Kær, Søren Knudsen

in the design phase of straw-fired boilers. Some of the primary model outputs include improved heat transfer rate predictions and detailed information about local deposit formation rates. This information is essential when boiler availability and efficiency is to be estimated. A stand-alone program has been...... accumulation rates encountered during straw combustion in grate-fired boilers. The sub-models have been based on information about the combustion and deposition properties of straw gathered from the literature and combined into a single Computational Fluid Dynamics (CFD) based analysis tool which can aid...... transfer mechanisms have a pronounced influence on the combustion pattern. The combined set of sub-models has been evaluated using the straw-fired boiler at Masnedø CHP plant as a test case. The predicted grate combustion and KCl release patterns are in qualitative agreement with experimental findings...

Mitigating the Risk of Stress Corrosion of Austenitic Stainless Steels in Advanced Gas Cooled Reactor Boilers

International Nuclear Information System (INIS)

Bull, A.; Owen, J.; Quirk, G.; G, Lewis; Rudge, A.; Woolsey, I.S.

2012-09-01

corrosion damage to the Type 316 superheater sections in the affected units an extensive programme of test work and plant modelling has been undertaken over a number of years. This has involved stress corrosion test work using full scale plant boiler simulations under a variety of feedwater chemistry conditions for both helical and serpentine boilers. Data from these investigations has then been used to construct models of the damage process that allow the risk of tube leaks due to stress corrosion cracking to be assessed. These models use plant feedwater chemistry and thermal-hydraulic data as inputs. The paper describes investigations of the risk of stress corrosion cracking in AGR boilers and the improvements in feedwater quality of the affected units to help mitigate the risk. (authors)

A dynamic model used for controller design of a coal fired once-through boiler-turbine unit

International Nuclear Information System (INIS)

Liu, Ji-Zhen; Yan, Shu; Zeng, De-Liang; Hu, Yong; Lv, You

2015-01-01

Supercritical OTB (once-through boiler) units with high steam temperature and pressure have been widely used in modern power plants due to their high cycle efficiency and less emissions. To ensure the effective operation of such power generation systems, it is necessary to build a model for the design of the overall control system. There are already detailed models of once-through boilers; however, their complexity prevents them from being applied in the controller design. This study describes a lumped parameter dynamic model that has a relatively low complexity while faithfully capturing the essential overall plant dynamics. The model structure was derived by fundamental physical laws utilizing reasonable simplifications and data analysis to avoid the phase transition position problem. Parameter identification for the model structure was completed using operational data from a 1000 MW ultra-supercritical OTB. The model was determined to be reasonable by comparison tests between computed data and measured data for both steady and dynamic states. The simplified model is verified to have appropriate fidelity in control system design to achieve effective and economic operation of the unit. - Highlights: • A simplified dynamic model of once-through boiler-turbine unit is given. • The essential dynamics of active power and throttle pressure is presented. • The change of phase transition position is avoided in modeling process. • The model has appropriate complexity and fidelity for controller design.

COAL-FIRED UTILITY BOILERS: SOLVING ASH DEPOSITION PROBLEMS; TOPICAL

International Nuclear Information System (INIS)

Christopher J. Zygarlicke; Donald P. McCollor; Steven A. Benson; Jay R. Gunderson

2001-01-01

The accumulation of slagging and fouling ash deposits in utility boilers has been a source of aggravation for coal-fired boiler operators for over a century. Many new developments in analytical, modeling, and combustion testing methods in the past 20 years have made it possible to identify root causes of ash deposition. A concise and comprehensive guidelines document has been assembled for solving ash deposition as related to coal-fired utility boilers. While this report accurately captures the current state of knowledge in ash deposition, note that substantial research and development is under way to more completely understand and mitigate slagging and fouling. Thus, while comprehensive, this document carries the title ''interim,'' with the idea that future work will provide additional insight. Primary target audiences include utility operators and engineers who face plant inefficiencies and significant operational and maintenance costs that are associated with ash deposition problems. Pulverized and cyclone-fired coal boilers are addressed specifically, although many of the diagnostics and solutions apply to other boiler types. Logic diagrams, ash deposit types, and boiler symptoms of ash deposition are used to aid the user in identifying an ash deposition problem, diagnosing and verifying root causes, determining remedial measures to alleviate or eliminate the problem, and then monitoring the situation to verify that the problem has been solved. In addition to a step-by-step method for identifying and remediating ash deposition problems, this guideline document (Appendix A) provides descriptions of analytical techniques for diagnostic testing and gives extensive fundamental and practical literature references and addresses of organizations that can provide help in alleviating ash deposition problems

Studies, Transport and Treatment Concept for Boilers from Berkeley NPP, England - 13599

International Nuclear Information System (INIS)

Wirendal, Bo; Saul, David; Robinson, Joe; Davidson, Gavin

2013-01-01

In November 2011 Studsvik was awarded a contract to transport five decommissioned boilers from the Berkeley Nuclear Licensed Site in the UK to the Studsvik Nuclear Site in Sweden for metal treatment and recycling. A key objective of the project was to remove the boilers from the site by 31 March 2012 and this was successfully achieved with all boilers off site by 22 March and delivered to Studsvik on 6 April. Four boilers have been processed and the fifth is planned for completion by end of December 2012.The project had many challenges including a very tight timescale and has been successfully delivered to cost and ahead of the baseline programme. This paper describes the project and the experience gained from treatment of the first four boilers. It is the first UK project to send large components overseas for recycling and provides new insight into the processing of Magnox gas-circuit components. (authors)

[Hazard evaluation modeling of particulate matters emitted by coal-fired boilers and case analysis].

Science.gov (United States)

Shi, Yan-Ting; Du, Qian; Gao, Jian-Min; Bian, Xin; Wang, Zhi-Pu; Dong, He-Ming; Han, Qiang; Cao, Yang

2014-02-01

In order to evaluate the hazard of PM2.5 emitted by various boilers, in this paper, segmentation of particulate matters with sizes of below 2. 5 microm was performed based on their formation mechanisms and hazard level to human beings and environment. Meanwhile, taking into account the mass concentration, number concentration, enrichment factor of Hg, and content of Hg element in different coal ashes, a comprehensive model aimed at evaluating hazard of PM2.5 emitted by coal-fired boilers was established in this paper. Finally, through utilizing filed experimental data of previous literatures, a case analysis of the evaluation model was conducted, and the concept of hazard reduction coefficient was proposed, which can be used to evaluate the performance of dust removers.

Optimization of Boiler Heat Load in Water-Heating Boiler-House

Directory of Open Access Journals (Sweden)

B. A. Bayrashevsky

2009-01-01

Full Text Available An analytical method for optimization of water-heating boiler loads has been developed on the basis of approximated semi-empirical dependences pertaining to changes of boiler gross efficiency due to its load. A complex (∂tух/∂ξΔξ is determined on the basis of a systematic analysis (monitoring of experimental data and the Y. P. Pecker’s formula for calculation of balance losses q2. This complex makes it possible to set a corresponding correction to a standard value of the boiler gross efficiency due to contamination of heating surfaces.Software means for optimization of water-heating boilers has been developed and it is recommended to be applied under operational conditions.

Ecological boiler modernization, feasible energy solutions

International Nuclear Information System (INIS)

Krcek, F.; Matev, M.; Sykora, J.; Chladek, J.

2005-01-01

Alstom Power, s.r.o., ALSTOM GROUP in Brno, Czech Republic is a successor of PBS (First Brno Machine Works). PBS was a well-known company in Bulgaria - mainly as Heating Power Plant (HPP) and Industrial Plant supplier of boilers, industrial steam turbines, milling systems, heat exchangers Btc. PBS has been privatised in two stages starting at1993 year. Alstom recently deals with boiler and heat exchanger products. Industrial turbine but has been sold to Siemens in 2004

ENERGY STAR Certified Boilers

Data.gov (United States)

U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 3.0 ENERGY STAR Program Requirements for Boilers that are effective as of October 1,...

Boilers, evaporators, and condensers

International Nuclear Information System (INIS)

Kakac, S.

1991-01-01

This book reports on the boilers, evaporators and condensers that are used in power plants including nuclear power plants. Topics included are forced convection for single-phase side heat exchangers, heat exchanger fouling, industrial heat exchanger design, fossil-fuel-fired boilers, once through boilers, thermodynamic designs of fossil fuel-first boilers, evaporators and condensers in refrigeration and air conditioning systems (with respect to reducing CFC's) and nuclear steam generators

Boiler house modernization through shared savings program

Energy Technology Data Exchange (ETDEWEB)

Breault, R.W. [Tecogen, Waltham, MA (United States)

1995-12-31

Throughout Poland as well as the rest of Eastern Europe, communities and industries rely on small heat only boilers to provide district and process heat. Together these two sectors produce about 85,000 MW from boilers in the 2 to 35 MW size range. The bulk of these units were installed prior to 1992 and must be completely overhauled to meet the emission regulations which will be coming into effect on January 1, 1998. Since the only practical fuel is coal in most cases, these boilers must be either retrofit with emission control technology or be replaced entirely. The question that arises is how to accomplish this given the current tight control of capital in Poland and other East European countries. A solution that we have for this problem is shared savings. These boilers are typically operating with a quiet low efficiency as compared to western standards and with excessive manual labor. Installing modernization equipment to improve the efficiency and to automate the process provides savings. ECOGY provides the funds for the modernization to improve the efficiency, add automation and install emission control equipment. The savings that are generated during the operation of the modernized boiler system are split between the client company and ECOGY for a number of years and then the system is turned over in entirety to the client. Depending on the operating capacity, the shared savings agreement will usually span 6 to 10 years.

Application of an empirical model in CFD simulations to predict the local high temperature corrosion potential in biomass fired boilers

International Nuclear Information System (INIS)

Gruber, Thomas; Scharler, Robert; Obernberger, Ingwald

2015-01-01

To gain reliable data for the development of an empirical model for the prediction of the local high temperature corrosion potential in biomass fired boilers, online corrosion probe measurements have been carried out. The measurements have been performed in a specially designed fixed bed/drop tube reactor in order to simulate a superheater boiler tube under well-controlled conditions. The investigated boiler steel 13CrMo4-5 is commonly used as steel for superheater tube bundles in biomass fired boilers. Within the test runs the flue gas temperature at the corrosion probe has been varied between 625 °C and 880 °C, while the steel temperature has been varied between 450 °C and 550 °C to simulate typical current and future live steam temperatures of biomass fired steam boilers. To investigate the dependence on the flue gas velocity, variations from 2 m·s −1 to 8 m·s −1 have been considered. The empirical model developed fits the measured data sufficiently well. Therefore, the model has been applied within a Computational Fluid Dynamics (CFD) simulation of flue gas flow and heat transfer to estimate the local corrosion potential of a wood chips fired 38 MW steam boiler. Additionally to the actual state analysis two further simulations have been carried out to investigate the influence of enhanced steam temperatures and a change of the flow direction of the final superheater tube bundle from parallel to counter-flow on the local corrosion potential. - Highlights: • Online corrosion probe measurements in a fixed bed/drop tube reactor. • Development of an empirical corrosion model. • Application of the model in a CFD simulation of flow and heat transfer. • Variation of boundary conditions and their effects on the corrosion potential

Assessment of Some Performance Characteristics of Refuse Boiler ...

African Journals Online (AJOL)

A pioneer palm oil boiler unit, in an immense power self-contained oil mill, impaired by many years of accumulated depreciation, was rebuilt in the pattern of a design-out scheme aimed primarily at rehabilitating the entire boiler system to a state of functionality. The research work studied the pre-maintenance and post ...

Control Properties of Bottom Fired Marine Boilers

DEFF Research Database (Denmark)

Solberg, Brian; Andersen, Palle; Karstensen, Claus M. S.

2005-01-01

This paper focuses on model analysis of a dynamic model of a bottom fired one-pass smoke tube boiler. Linearised versions of the model are analysed to determine how gain, time constants and right half plane zeros (caused by the shrink-and-swell phenomenon) depend on the steam flow load. Furthermore...... the interactions in the system are inspected to analyse potential benefit from using a multivariable control strategy in favour of the current strategy based on single loop theory. An analysis of the nonlinear model is carried out to further determine the nonlinear characteristics of the boiler system...

Dynamic simulation of a circulating fluidized bed boiler system part I: Description of the dynamic system and transient behavior of sub-models

International Nuclear Information System (INIS)

Kim, Seong Il; Choi, Sang Min; Yang, Jong In

2016-01-01

Dynamic performance simulation of a CFB boiler in a commercial-scale power plant is reported. The boiler system was modeled by a finite number of heat exchanger units, which are sub-grouped into the gas-solid circulation loop, the water-steam circulation loop, and the inter-connected heat exchangers blocks of the boiler. This dynamic model is an extension from the previously reported performance simulation model, which was designed to simulate static performance of the same power plant, where heat and mass for each of the heat exchanger units were balanced for the inter-connected heat exchanger network among the fuel combustion system and the water-steam system. Dynamic performance simulation was achieved by calculating the incremental difference from the previous time step, and progressing for the next time step. Additional discretization of the heat exchanger blocks was necessary to accommodate the dynamic response of the water evaporation and natural circulation as well as the transient response of the metal temperature of the heat exchanger elements. Presentation of the simulation modeling is organized into two parts; system configuration of the model plant and the general approach of the simulation are presented along with the transient behavior of the sub-models in Part I. Dynamic sub-models were integrated in terms of the mass flow and the heat transfer for simulating the CFB boiler system. Dynamic simulation for the open loop response was performed to check the integrated system of the water-steam loop and the solid-gas loop of the total boiler system. Simulation of the total boiler system which includes the closed-loop control system blocks is presented in the following Part II

Dynamic simulation of a circulating fluidized bed boiler system part I: Description of the dynamic system and transient behavior of sub-models

Energy Technology Data Exchange (ETDEWEB)

Kim, Seong Il; Choi, Sang Min; Yang, Jong In [Dept. of Mechanical Engineering, Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

2016-12-15

Dynamic performance simulation of a CFB boiler in a commercial-scale power plant is reported. The boiler system was modeled by a finite number of heat exchanger units, which are sub-grouped into the gas-solid circulation loop, the water-steam circulation loop, and the inter-connected heat exchangers blocks of the boiler. This dynamic model is an extension from the previously reported performance simulation model, which was designed to simulate static performance of the same power plant, where heat and mass for each of the heat exchanger units were balanced for the inter-connected heat exchanger network among the fuel combustion system and the water-steam system. Dynamic performance simulation was achieved by calculating the incremental difference from the previous time step, and progressing for the next time step. Additional discretization of the heat exchanger blocks was necessary to accommodate the dynamic response of the water evaporation and natural circulation as well as the transient response of the metal temperature of the heat exchanger elements. Presentation of the simulation modeling is organized into two parts; system configuration of the model plant and the general approach of the simulation are presented along with the transient behavior of the sub-models in Part I. Dynamic sub-models were integrated in terms of the mass flow and the heat transfer for simulating the CFB boiler system. Dynamic simulation for the open loop response was performed to check the integrated system of the water-steam loop and the solid-gas loop of the total boiler system. Simulation of the total boiler system which includes the closed-loop control system blocks is presented in the following Part II.

Life extension of MAPS-2 by replacement of boiler hairpin type heat exchangers

International Nuclear Information System (INIS)

Tripathi, J.C.; Rastogi, S.K.; Rastogi, A.K.

2006-01-01

The steam generating equipment in MAPS-1 and 2 are Hairpin type comprises of eight boiler assemblies arranged in two banks of four boilers each. Each hairpin type heat exchangers consist of 195 Monel-400 tubes of 12.7 mm OD x 1.24 mm WT. One boiler assembly consists of eleven inverted U type heat exchangers (called hairpin type heat exchangers) mounted in parallel on inlet and outlet heavy water manifolds and connected to steam drum through individual short riser. Heavy water flows through these tubes where as feed water enters the shell at the bottom of one leg called pre-heat leg. After commissioning of MAPS-2 in 1985, five hairpins of MAPS-2 developed leak during the course of operation by the year 1999. Absence of physical access for health assessment of steam generator tube and lack of provision for tube sheet cleaning to remove the deposits on feed water side had caused pile and resulted in tube failures by under deposit pitting corrosion. All the 88 hairpins of MAPS-2 were replaced to extend the plant life when MAPS-2 was taken out of grid for En-masse Coolant Channel Replacement job (EMCCR) in the year 2001 - 03. The long shutdown of MAPS units for EMCCR was considered to be cost effective since unscheduled plant shut downs on account of tube leaks could be avoided. (author)

PAH emissions from old and new types of domestic hot water boilers.

Science.gov (United States)

Horak, Jiri; Kubonova, Lenka; Krpec, Kamil; Hopan, Frantisek; Kubesa, Petr; Motyka, Oldrich; Laciok, Vendula; Dej, Milan; Ochodek, Tadeas; Placha, Daniela

2017-06-01

Five different domestic heating boilers (automatic, over-fire, with down-draft combustion and gasification) and three types of fuel (lignite, wood and mixed fuel) were examined in 25 combustion tests and correlated with the emissions of particulate matter (PM), carbon monoxide (CO), total organic carbon (TOC) and 12 polycyclic aromatic hydrocarbons (PAHs with MW = 178-278 g/mol) focusing on particle phase. However, the distribution of 12 PAHs in gas phase was considered as well due to the presence mainly of lighter PAHs in gas phase. The PAHs, as well as the CO and TOC, are the indicators of incomplete combustion, and in this study PAH emission increased significantly with increasing emissions of CO and TOC. The PAHs were mainly detected on PM 2.5 , their contents were increasing linearly with increasing PM 2.5 emissions. The highest emission factors of PAHs were measured for boilers of old construction, such as over-fire boiler (5.8-929 mg/kg) and boiler with down-draft combustion (3.1-54.1 mg/kg). Modern types of boilers produced much lower emissions of PAHs, in particular, automatic boiler (0.3-3.3 mg/kg) and gasification boilers (0.2-6.7 mg/kg). In general, the inefficient combustion at reduced output of boilers generated 1.4-17.7 times more emissions of PAHs than the combustion at nominal output of boilers. It is recommended to operate boilers at nominal output with sufficient air supply and to use the proper fuel to minimise PAHs emissions from domestic heating appliances. Copyright © 2017 Elsevier Ltd. All rights reserved.

Computation Modeling and Assessment of Nanocoatings for Ultra Supercritical Boilers

Energy Technology Data Exchange (ETDEWEB)

J. Shingledecker; D. Gandy; N. Cheruvu; R. Wei; K. Chan

2011-06-21

Forced outages and boiler unavailability of coal-fired fossil plants is most often caused by fire-side corrosion of boiler waterwalls and tubing. Reliable coatings are required for Ultrasupercritical (USC) application to mitigate corrosion since these boilers will operate at a much higher temperatures and pressures than in supercritical (565 C {at} 24 MPa) boilers. Computational modeling efforts have been undertaken to design and assess potential Fe-Cr-Ni-Al systems to produce stable nanocrystalline coatings that form a protective, continuous scale of either Al{sub 2}O{sub 3} or Cr{sub 2}O{sub 3}. The computational modeling results identified a new series of Fe-25Cr-40Ni with or without 10 wt.% Al nanocrystalline coatings that maintain long-term stability by forming a diffusion barrier layer at the coating/substrate interface. The computational modeling predictions of microstructure, formation of continuous Al{sub 2}O{sub 3} scale, inward Al diffusion, grain growth, and sintering behavior were validated with experimental results. Advanced coatings, such as MCrAl (where M is Fe, Ni, or Co) nanocrystalline coatings, have been processed using different magnetron sputtering deposition techniques. Several coating trials were performed and among the processing methods evaluated, the DC pulsed magnetron sputtering technique produced the best quality coating with a minimum number of shallow defects and the results of multiple deposition trials showed that the process is repeatable. scale, inward Al diffusion, grain growth, and sintering behavior were validated with experimental results. The cyclic oxidation test results revealed that the nanocrystalline coatings offer better oxidation resistance, in terms of weight loss, localized oxidation, and formation of mixed oxides in the Al{sub 2}O{sub 3} scale, than widely used MCrAlY coatings. However, the ultra-fine grain structure in these coatings, consistent with the computational model predictions, resulted in accelerated Al

Robust H(infinity) tracking control of boiler-turbine systems.

Science.gov (United States)

Wu, J; Nguang, S K; Shen, J; Liu, G; Li, Y G

2010-07-01

In this paper, the problem of designing a fuzzy H(infinity) state feedback tracking control of a boiler-turbine is solved. First, the Takagi and Sugeno fuzzy model is used to model a boiler-turbine system. Next, based on the Takagi and Sugeno fuzzy model, sufficient conditions for the existence of a fuzzy H(infinity) nonlinear state feedback tracking control are derived in terms of linear matrix inequalities. The advantage of the proposed tracking control design is that it does not involve feedback linearization technique and complicated adaptive scheme. An industrial boiler-turbine system is used to illustrate the effectiveness of the proposed design as compared with a linearized approach. 2010 ISA. Published by Elsevier Ltd. All rights reserved.

Ultrasonic boiler inspection and economic analysis guidelines

International Nuclear Information System (INIS)

Anon.

1987-01-01

Boiler tube failures cause approximately 6% availability loss of large fossil-fired power generating plants. This loss can be reduced by systematic approaches using ultrasonic examination and root cause failure analysis methods. Two projects sponsored by EPRI have provided utility engineers with guidelines for performing ultrasonic examinations and with details on 22 types of tube failure mechanisms. A manual has been published that provides descriptions of typical locations, superficial appearances, damage mechanisms, metallurgy, microstructural changes, likely root causes, and potential corrective actions. Application of the principles in the manual is being demonstrated in an EPRI-funded project at 10 electric utilities over the next two years. Guidelines have been published that prescribe the activities necessary for ultrasonic examinations of boiler tubes. Eight essential elements of a boiler examination should be performed to assure that possible economic benefits are obtained. Work was supported by EPRI under RP 1890 and RP 1865. A software package has been developed for effectively planning inspections for wall thinning in fossil-fired boiler tubing. The software assists in minimizing costs associated with maintenance, such as inspection and repair, while the life of the boiler is maximized

A study on the boiler efficiency influenced by the boiler operation parameter in fossil power plant

International Nuclear Information System (INIS)

Kwon, Y. S.; Suh, J. S.

2002-01-01

The main reason to analyze the boiler operation parameter in fossil power plant is to increase boiler high efficiency and energy saving movement in the government. This study intends to have trend and analyze the boiler efficiency influenced by the boiler parameter in sub-critical and super-critical type boiler

CFD investigation of flow through internally riffled boiler tubes

DEFF Research Database (Denmark)

Rasmussen, Christian; Houbak, Niels; Sørensen, Jens Nørkær

1997-01-01

In this paper we show how to model the swirling flow in an internally riffled boiler tube. The flow field is visualized and the results are compared with measurements.......In this paper we show how to model the swirling flow in an internally riffled boiler tube. The flow field is visualized and the results are compared with measurements....

Investigation of transient behaviour of combi boiler type appliances for domestic hot water

International Nuclear Information System (INIS)

Atmaca, Ayşe Uğurcan; Erek, Aytunç; Altay, Hürrem Murat

2015-01-01

Combi boiler type appliances heating both space and water demanded for use and consuming natural gas as the energy source are one of the most common branches of the household goods. This study touches mainly on two types of combi boiler concepts to investigate only domestic hot water (DHW) heating function since highly efficient condensing appliances have been manufactured in terms of space heating. First concept has the normal working configuration of the heat exchangers of a standard combi boiler; whereas, the second has the opposite operation order of the heat exchangers. 1D transient energy equations have been constructed with the help of the laws of thermodynamics in order to model the heat exchangers in a standard combi boiler. After obtaining a general mathematical model for the standard combi boiler, the energy equations have been discretised with finite difference scheme, and solved numerically in Matlab ® . Subsequently, numerical results are validated experimentally in different working modes of a standard appliance. As the last step, similar results are obtained for the second proposed concept using the related equations of the standard combi model to compare both concepts on a numerical basis. - Highlights: • 1D theoretical model of a combi boiler was constructed and verified experimentally. • Preliminary estimations will be obtained from the model about the laboratory tests. • Number of the laboratory tests will be decreased thanks to the theoretical model. • The model was used to compare the transient behaviour of two kinds of combi boilers. • The second combi boiler alternative to standard one has a higher comfort potential

30 CFR 57.13030 - Boilers.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Boilers. 57.13030 Section 57.13030 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-UNDERGROUND METAL AND NONMETAL MINES Compressed Air and Boilers § 57.13030 Boilers. (a) Fired pressure vessels (boilers) shall be equipped with water level gauges, pressure...

30 CFR 56.13030 - Boilers.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Boilers. 56.13030 Section 56.13030 Mineral... HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Compressed Air and Boilers § 56.13030 Boilers. (a) Fired pressure vessels (boilers) shall be equipped with water level gauges, pressure gauges...

Analysis of residual swirl in tangentially-fired natural gas-boiler

International Nuclear Information System (INIS)

Hasril Hasini; Muhammad Azlan Muad; Mohd Zamri Yusoff; Norshah Hafeez Shuaib

2010-01-01

This paper describes the investigation on residual swirl flow in a 120 MW natural gas, full-scale, tangential-fired boiler. Emphasis is given towards the understanding of the behavior of the combustion gas flow pattern and temperature distribution as a result of the tangential firing system of the boiler. The analysis was carried out based on three-dimensional computational modeling on full scale boiler with validation from key design parameter as well as practical observation. Actual operating parameters of the actual boiler are taken as the boundary conditions for this modeling. The prediction of total heat flux was found to be in agreement with the key design parameter while the residual swirl predicted at the upper furnace agrees qualitatively with the practical observation. Based on this comparison, detail analysis was carried out for comprehensive understanding on the generation and destruction of the residual swirl behavior in boiler especially those with high capacity. (author)

30 CFR 77.413 - Boilers.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Boilers. 77.413 Section 77.413 Mineral... Mechanical Equipment § 77.413 Boilers. (a) Boilers shall be equipped with guarded, well-maintained water... the gages shall be kept clean and free of scale and rust. (b) Boilers shall be equipped with automatic...

Research, Development and Demonstration of Bio-Mass Boiler for Food Industry

Energy Technology Data Exchange (ETDEWEB)

Fisher, Steve [Burns & McDonnell, Inc., Kansas City, MO (United States); Knapp, David [Burns & McDonnell, Inc., Kansas City, MO (United States)

2012-07-01

Frito-Lay is working to reduce carbon emissions from their manufacturing plants. As part of this effort, they invested in a biomass-fired boiler at the Topeka, Kansas, plant. Frito-Lay partnered with Burns & McDonnell Engineering, Inc. and CPL Systems, Inc., to design and construct a steam producing boiler using carbon neutral fuels such as wood wastes (e.g. tree bark), shipping pallets, and used rubber vehicle tires. The U.S. Department of Energy (DOE) joined with Frito-Lay, Burns & McDonnell, and CPL to analyze the reductions in carbon dioxide (CO₂) emissions that result from use of biomass-fired boilers in the food manufacturing environment. DOE support provided for the data collection and analysis, and reporting necessary to evaluate boiler efficiencies and reductions in CO₂ emissions. The Frito-Lay biomass-fired boiler has resulted in significant reductions in CO₂ emissions from the Topeka production facility. The use of natural gas has been reduced by 400 to 420 million standard cubic feet per year with corresponding reductions of 24,000 to 25,000 tons of CO₂. The boiler does require auxiliary functions, however, that are unnecessary for a gas-fired boiler. These include heavy motors and fans for moving fuel and firing the boiler, trucks and equipment for delivering the fuel and moving at the boiler plant, and chippers for preparing the fuel prior to delivery. Each of these operations requires the combustion of fossil fuels or electricity and has associated CO₂ emissions. Even after accounting for each of these auxiliary processes, however, the biomass-fired boiler results in net emission reductions of 22,500 to 23,500 tons of CO₂ per year.

Materials and boiler rig testing to support chemical cleaning of once-through AGR boilers

International Nuclear Information System (INIS)

Tice, D.R.; Platts, N.; Raffel, A.S.; Rudge, A.

2002-01-01

chosen. This paper describes the results of the latter two activities: additional materials testing necessary to support a full scale plant clean and the trial clean on a model boiler rig replicating a single boiler tube together with the pre- and post-clean thermohydraulic behaviour. (authors)

Up-date on cyclone combustion and cyclone boilers

Energy Technology Data Exchange (ETDEWEB)

Carmo, Felipe Alfaia do; Nogueira, Manoel Fernandes Martins; Rocha, Rodrigo Carnera Castro da; Gazel, Hussein Felix; Martins, Diego Henrique dos Reis [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Campus Universitario Jose da Silveira Netto], E-mails: mfmn@ufpa.br, mfmn@ufpa.br

2010-07-01

The boiler concept has been around for more than 70 years, and there are many types available. Boilers provide steam or hot water for industrial and commercial use. The Federal University of Para (UFPA) through the research group EBMA (Energy,Biomass and Environment) has been developing cyclonic furnace with a water wall, a boiler, aiming to use regional timbers (sawdust) and agro-industries residues as fuel to produce steam to be used in industrial processes as well as in power generation,. The use of cyclonic combustion for burning waste instead of burning in a fixed bed is mainly due to two factors efficiency improvement causing a more compact boiler and less risk of explosion, since their process does not generate an accumulation of volatile. Present state-of-art for commercial cyclone boilers has as set up a cyclone combustor with two combustion chambers, in fluid communication, where there ducts for supplying air and fuel directly into the first chamber and for forming a cyclonic flow pattern and a heat exchanger surrounding the second chamber for keeping low combustion temperature in both chambers. This paper shows the results of a literature review about design, construction and operation of cyclonic boilers using solid, liquid or gaseous fuel. This information has been used for the design of a cyclone boiler to be constructed at UFPA for research purposes and its basic concept is presented at the end of this article. (author)

TRIUMF: Five-year plan

International Nuclear Information System (INIS)

Anon.

1995-01-01

The Canadian government recently announced approval of a five-year-plan for TRIUMF, giving the Vancouver Laboratory assured funding until the year 2000. Besides continuation of the multidisciplinary cyclotron, this will allow construction of ISAC-1, a new on-line isotope separator. At the same time, TRIUMF will also be responsible for Canadian ''in-kind'' contributions to international science at CERN's LHC proton-proton collider (see page 1). The federal plan strengthens TRIUMF's role as a national facility, run by a consortium of universities across Canada. In addition, TRIUMF will have even stronger international links. The federal government has allocated a total of $166.6 million to TRIUMF over the next five years. In addition, the provincial British Columbia government, a long-time supporter of TRIUMF, has already agreed to provide approximately $10 million for conventional construction. The nature of the accelerator contributions to the LHC has not been finally decided, although two areas are under discussion - the upgrade of the accelerator chain, and construction of the two 'beam cleaning' insertions. The former would involve provision of various new systems (radiofrequency, magnets, power supplies, kickers, etc) for the Booster, PS and SPS synchrotrons; indeed activity is already underway in some areas, such as model studies for a new 40 MHz system for the PS. The acronym of the new facility, ISAC-1, is short for Isotope Separator & Accelerator. A prototype first stage already exists in TRIUMF. ISAC-1 will use the intense proton beam from the TRIUMF cyclotron to create powerful beams of exotic, short-lived, radioactive nuclei which will be accelerated in a new structure

ENERGY STAR Certified Commercial Boilers

Data.gov (United States)

U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 1.0 ENERGY STAR Program Requirements for Commercial Boilers that are effective as of...

The orificing of once-through boilers for gas-cooled reactors

International Nuclear Information System (INIS)

Collier, J.G.; Whitmarsh-Everiss, M.J.

1986-01-01

The boilers at Hinkley Point B, Hunterston B (which are built to a common design) and Hartlepool and Heysham (which are identical to each other although different from Hinkley B/Hunterston B) are discussed. Heysham II and Torness have boilers developed from the Hinkley B/Hunterston B design. The boiler design is explained and the problems encountered are presented. The study presented in this address highlights the potential sensitivity of the performance of once-through boilers to the following factors - the uniformity of the gas inlet temperature profile, the choice of the operating point on the boiler characteristic (preferably this should be where the performance of the unit is not too sensitive to the primary side temperature and flow distribution); this can be achieved by greater levels of orificing reducing the steady state gains, and the various plant operating states which introduce asymmetries into the boundary conditions for the boiler. A number of computer codes have been used to model boiler performance. Using these, a new design was proposed for boiler feed regulating orifices and these revised orifices were installed during outages on the two Heysham reactors in 1985. (U.K.)

Modern power station practice mechanical boilers, fuel-, and ash-handling plant

CERN Document Server

Sherry, A; Cruddace, AE

2014-01-01

Modern Power Station Practice, Second Edition, Volume 2: Mechanical (Boilers, Fuel-, and Ash-Handling Plant) focuses on the design, manufacture and operation of boiler units and fuel-and ash-handling plants.This book is organized into five main topics-furnace and combustion equipment, steam and water circuits, ancillary plant and fittings, dust extraction and draught plant, and fuel-and ash-handling plant.In these topics, this text specifically discusses the influence of nature of coal on choice of firing equipment; oil-burner arrangements, ignition and control; disposition of the heating surf

Distributed parameter modeling and simulation for the evaporation system of a controlled circulation boiler based on 3-D combustion monitoring

International Nuclear Information System (INIS)

Chu Yuntao; Lou Chun; Cheng Qiang; Zhou Huaichun

2008-01-01

In this paper, a dynamic, distributed parameter model for the evaporation system of a controlled circulation boiler was developed. As an essential basis, the 3-D temperature distribution and the average emissivity of the particle phase inside its furnace can be got by a flame image processing technique from multiple, visible flame image detectors in a real-time combustion monitoring system. Then the transient, 2-D radiation flux can be obtained by solving a set of energy balance equations for the water wall elements, which serves as a distributed boundary condition for the dynamic, distributed parameter model proposed for the evaporation system. For large change of the boiler load, two important parameters, the correction factor of equivalent flame emissivity and the coefficient of the steam mass flow rate at the outlet of the drum, were determined using the operation data from a 300 MW boiler. The model was validated by comparing the simulation results for some main steam parameters of the system with those from measurements. Besides that, the transient distributions of the parameters, such as the steam quality and the mass velocity, were predicted by the model. This model can be used for on-line calculation or off-line prediction of the local abnormal phenomena occurring on the water walls, forming an important basis to effectively evaluate the security and the reliability of a power plant boiler

Electric utility CFB boilers

International Nuclear Information System (INIS)

Fairbanks, D.A.

1991-01-01

This paper reports on Circulating Fluidized Bed (CFB) boiler technology which caught the attention of boiler users: first for its technical advantages of reduced air emissions and low grade fuel tolerance, then later for its problems in becoming a reliable process. Refractory longevity and fuel feed reliability plagued a number of new installations. The efficacy of CFB technology is now more assured with the recent success of Texas-New Mexico Power Company's 160 MWe CFB based units, the world's largest operating CFB boilers. Most of the more notable CFB development problems have been successfully addressed by these units. The TNP units have demonstrated that CFB's can reliable produce high capacity factors at low emission rates using a fuel that has traditionally hampered the operation of pulverized coal (PC) boilers and without the attendant problems associated with sulfur scrubbers required by PC boilers

Mixing Studies in a 1:60 scale model of a cornerfired boiler with OFA

DEFF Research Database (Denmark)

Matlok, Simon; Scheel Larsen, Poul; Gjernes, Erik

1998-01-01

In a model of a boiler, concentration distributions of injected gas into a swirling bulk flow are determined from quantitative laser-sheet visualization. Together with LDA-measurements of velocity fields this describes the mixing process and its efficiency expressed by several measures (unmixedness...

Dynamic Boiler Performance

DEFF Research Database (Denmark)

Sørensen, Kim

Traditionally, boilers have been designed mainly focussing on the static operation of the plant. The dynamic capability has been given lower priority and the analysis has typically been limited to assuring that the plant was not over-stressed due to large temperature gradients. New possibilities...... developed. Analyzing boilers for dynamic operation gives rise to a number of opposing aims: shrinking and swelling, steam quality, stress levels, control system/philosophy, pressurization etc. Common for these opposing aims is that an optimum can be found for selected operation conditions. The framework has...... for buying and selling energy has increased the focus on the dynamic operation capability, efciency, emissions etc. For optimizing the design of boilers for dynamic operation a quantication of the dynamic capability is needed. A framework for optimizing design of boilers for dynamic operation has been...

Thermal-hydraulic analysis of a 600 MW supercritical CFB boiler with low mass flux

International Nuclear Information System (INIS)

Pan Jie; Yang Dong; Chen Gongming; Zhou Xu; Bi Qincheng

2012-01-01

Supercritical Circulating Fluidized Bed (CFB) boiler becomes an important development trend for coal-fired power plant and thermal-hydraulic analysis is a key factor for the design and operation of water wall. According to the boiler structure and furnace-sided heat flux, the water wall system of a 600 MW supercritical CFB boiler is treated in this paper as a flow network consisting of series-parallel loops, pressure grids and connecting tubes. A mathematical model for predicting the thermal-hydraulic characteristics in boiler heating surface is based on the mass, momentum and energy conservation equations of these components, which introduces numerous empirical correlations available for heat transfer and hydraulic resistance calculation. Mass flux distribution and pressure drop data in the water wall at 30%, 75% and 100% of the boiler maximum continuous rating (BMCR) are obtained by iteratively solving the model. Simultaneity, outlet vapor temperatures and metal temperatures in water wall tubes are estimated. The results show good heat transfer performance and low flow resistance, which implies that the water wall design of supercritical CFB boiler is applicable. - Highlights: → We proposed a model for thermal-hydraulic analysis of boiler heating surface. → The model is applied in a 600 MW supercritical CFB boiler. → We explore the pressure drop, mass flux and temperature distribution in water wall. → The operating safety of boiler is estimated. → The results show good heat transfer performance and low flow resistance.

India's first 100,000 lbs/hr atmospheric bed boiler

International Nuclear Information System (INIS)

Mahajan, S.K.

1991-01-01

This paper covers the operating experience at the Petrochemical Complex of Hindustan Polymers, a Member Company of the UB Group, India, on the India's first 100,000 Lbs/hr atmospheric fluidized bed boiler supplied by Bharat Heavy Electricals Ltd., India. This atmospheric fluidized bed boiler is in operation for over 7 years with over 51,000 operating hours. The paper covers the details of onstream hours, actual thermal efficiency achieved, type of coal used and operational advantages of such boilers as per experience of Hindustan Polymers. Paper also highlights the maintenance and equipment problems as well as the developments which have taken place to overcome such problems. Details of experience in the operation of this boiler with baghouse system using abrasive and high ash coal are also covered

Increase of energy efficiency in proportional adjusting of flow rate in the boiler circuit

OpenAIRE

Artamonov Pavel A.; Kurilenko Nikolai I.; Mamontov Gennady Ya.

2017-01-01

The article presents the results of theoretical studies in the field of the boiler circuit operating modes for the boiler rooms operating by the independent heat supply scheme. The 3D model of a boiler circuit for a boiler room with 3 MW rated output was developed, based on which there was made an estimation of the boiler pump performance indicators. There is proposed a method for reducing energy costs for the operation of the pumping equipment of the boiler circuit.

Improving boiler unit performance using an optimum robust minimum-order observer

International Nuclear Information System (INIS)

Moradi, Hamed; Bakhtiari-Nejad, Firooz

2011-01-01

Research highlights: → Multivariable model of a boiler unit with uncertainty. → Design of a robust minimum-order observer. → Developing an optimal functional code in MATLAB environment. → Finding optimum region of observer-based controller poles. → Guarantee of robust performance in the presence of parametric uncertainties. - Abstract: To achieve a good performance of the utility boiler, dynamic variables such as drum pressure, steam temperature and water level of drum must be controlled. In this paper, a linear time invariant (LTI) model of a boiler system is considered in which the input variables are feed-water and fuel mass rates. Due to the inaccessibility of some state variables of boiler system, a minimum-order observer is designed based on Luenberger's model to gain an estimate state x-tilde of the true state x. Low cost of design and high accuracy of states estimation are the main advantages of the minimum-order observer; in comparison with previous designed full-order observers. By applying the observer on the closed-loop system, a regulator system is designed. Using an optimal functional code developed in MATLAB environment, desired observer poles are found such that suitable time response specifications of the boiler system are achieved and the gain and phase margin values are adjusted in an acceptable range. However, the real dynamic model may associate with parametric uncertainties. In that case, optimum region of poles of observer-based controller are found such that the robust performance of the boiler system against model uncertainties is guaranteed.

Application of zonal combustion model for on-line furnace analysis of 575MW tangential coal firing boiler

Energy Technology Data Exchange (ETDEWEB)

Chudnovsky, B.; Karasina, E.; Livshits, B.; Talanker, A. [Israel Electric Corporation (Israel). Engineering Division

1999-07-01

An advanced code for calculating heat transfer in the boiler of furnaces is considered. The code can be used to compute the flue gas temperature in the furnace volume and the absorbed and incident heat fluxes. The number of zones in the furnace, the points of the injection of the fuel, air and flue gas recirculation (if applicable), the radiative heat transfer properties of the flue gases as well as all the factors determining performance are taken into account in the calculation. The code also predicts water wall and superheater temperature and NO{sub x} emission. The validity of the proposed model was confirmed by comparison between calculated and measured values. The predicted results show good agreement with the experimental data. The code developed is for engineers using advanced PCS at the stage of designing new boilers as well as when retrofitting and adjusting boilers already in operation. In comparison with existing complex computational models the proposed system can be used in modern monitoring systems for the furnace diagnostic problems including NO{sub x} emission. 7 refs., 11 figs.

Experimental investigation and mathematical modelling of wood combustion in a moving grate boiler

International Nuclear Information System (INIS)

Zhang, Xiaohui; Chen, Qun; Sharifi, Vida; Swithenbank, Jim; Bradford, Richard

2010-01-01

The use of biomass to generate energy offers significant environmental advantages for the reduction in emissions of greenhouse gases. The main objective of this study was to investigate the performance of a small scale biomass heating plant: i.e. combustion characteristics and emissions. An extensive series of experimental tests was carried out at a small scale residential biomass heating plant i.e. wood chip fired boiler. The concentrations of CO, NO x , particulate matter in the flue gas were measured. In addition, mathematical modelling work using FLIC and FLUENT codes was carried out in order to simulate the overall performance of the wood fired heating system. Results showed that pollutant emissions from the boiler were within the relative emission limits. Mass concentration of CO emission was 550-1600 mg/m 3 (10% O 2 ). NO x concentration in the flue gas from the wood chips combustion varied slightly between 28 and 60 ppmv. Mass concentration of PM 10 in the flue gas was 205 mg/m 3 (10% O 2 ) The modelling results showed that most of the fuel was burnt inside the furnace and little CO was released from the system due to the high flue gas temperature in the furnace. The injection of the secondary air provided adequate mixing and favourable combustion conditions in the over-bed chamber in the wood chips fired boiler. This study has shown that the use of wood heating system result in much lower CO 2 emissions than from a fossil fuel e.g. coal fired heating system. (author)

Coal reburning technology for cyclone boilers

International Nuclear Information System (INIS)

Yagiela, A.S.; Maringo, G.J.; Newell, R.J.; Farzan, H.

1990-01-01

Babcock and Wilcox has obtained encouraging results from engineering feasibility and pilot-scale proof-of-concept studies of coal reburning for cyclone boiler NO x control. Accordingly, B and W completed negotiations for a clean coal cooperative agreement with the Department of Energy to demonstrate coal reburning technology for cyclone boilers. The host site for the demonstration is the Wisconsin Power and Light (WP and L) Company's 100MWe Nelson Dewey Station. Reburning involves the injection of a supplemental fuel (natural gas, oil, or coal) into the main furnace to produce locally reducing stoichiometric conditions which convert the NO x produced therein to molecular nitrogen, thereby reducing overall NO x emissions. There are currently no commercially-demonstrated combustion modification techniques for cyclone boilers which reduce NO x emissions. The emerging reburning technology offers cyclone boiler operators a promising alternative to expensive flue gas cleanup techniques for NO x emission reduction. This paper reviews baseline testing results at the Nelson Dewey Station and pilot-scale results simulating Nelson Dewey operation using pulverized coal (PC) as the reburning fuel. Outcomes of the model studies as well as the full-scale demonstration preliminary design are discussed

An optimising controller for Hinkley Point B AGR boilers

International Nuclear Information System (INIS)

Wells, C.

1986-01-01

The improvements to the control system at Hinkley Point 'B' Power Station has as one of its objectives the provision of a half unit valve controller. This will enable the asymmetry between the boiler half units, which is a feature of current operation, to be reduced. The use of an on-line boiler model in conjunction with this facility will allow the risk to the boilers from corrosion, creep, and vibration to be assessed and held at the minimum attainable value, thereby prolonging plant life whilst maximising output and efficiency. (author)

Applied Gaussian Process in Optimizing Unburned Carbon Content in Fly Ash for Boiler Combustion

Directory of Open Access Journals (Sweden)

Chunlin Wang

2017-01-01

Full Text Available Recently, Gaussian Process (GP has attracted generous attention from industry. This article focuses on the application of coal fired boiler combustion and uses GP to design a strategy for reducing Unburned Carbon Content in Fly Ash (UCC-FA which is the most important indicator of boiler combustion efficiency. With getting rid of the complicated physical mechanisms, building a data-driven model as GP is an effective way for the proposed issue. Firstly, GP is used to model the relationship between the UCC-FA and boiler combustion operation parameters. The hyperparameters of GP model are optimized via Genetic Algorithm (GA. Then, served as the objective of another GA framework, the predicted UCC-FA from GP model is utilized in searching the optimal operation plan for the boiler combustion. Based on 670 sets of real data from a high capacity tangentially fired boiler, two GP models with 21 and 13 inputs, respectively, are developed. In the experimental results, the model with 21 inputs provides better prediction performance than that of the other. Choosing the results from 21-input model, the UCC-FA decreases from 2.7% to 1.7% via optimizing some of the operational parameters, which is a reasonable achievement for the boiler combustion.

49 CFR 230.47 - Boiler number.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Boiler number. 230.47 Section 230.47..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Steam Gauges § 230.47 Boiler number. (a) Generally. The builder's number of the boiler, if known, shall...

Improving boiler unit performance using an optimum robust minimum-order observer

Energy Technology Data Exchange (ETDEWEB)

Moradi, Hamed; Bakhtiari-Nejad, Firooz [Energy and Control Centre of Excellence, Department of Mechanical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)

2011-03-15

To achieve a good performance of the utility boiler, dynamic variables such as drum pressure, steam temperature and water level of drum must be controlled. In this paper, a linear time invariant (LTI) model of a boiler system is considered in which the input variables are feed-water and fuel mass rates. Due to the inaccessibility of some state variables of boiler system, a minimum-order observer is designed based on Luenberger's model to gain an estimate state x of the true state x. Low cost of design and high accuracy of states estimation are the main advantages of the minimum-order observer; in comparison with previous designed full-order observers. By applying the observer on the closed-loop system, a regulator system is designed. Using an optimal functional code developed in MATLAB environment, desired observer poles are found such that suitable time response specifications of the boiler system are achieved and the gain and phase margin values are adjusted in an acceptable range. However, the real dynamic model may associate with parametric uncertainties. In that case, optimum region of poles of observer-based controller are found such that the robust performance of the boiler system against model uncertainties is guaranteed. (author)

Stress-Assisted Corrosion in Boiler Tubes

Energy Technology Data Exchange (ETDEWEB)

Preet M Singh; Steven J Pawel

2006-05-27

A number of industrial boilers, including in the pulp and paper industry, needed to replace their lower furnace tubes or decommission many recovery boilers due to stress-assisted corrosion (SAC) on the waterside of boiler tubes. More than half of the power and recovery boilers that have been inspected reveal SAC damage, which portends significant energy and economic impacts. The goal of this project was to clarify the mechanism of stress-assisted corrosion (SAC) of boiler tubes for the purpose of determining key parameters in its mitigation and control. To accomplish this in-situ strain measurements on boiler tubes were made. Boiler water environment was simulated in the laboratory and effects of water chemistry on SAC initiation and growth were evaluated in terms of industrial operations. Results from this project have shown that the dissolved oxygen is single most important factor in SAC initiation on carbon steel samples. Control of dissolved oxygen can be used to mitigate SAC in industrial boilers. Results have also shown that sharp corrosion fatigue and bulbous SAC cracks have similar mechanism but the morphology is different due to availability of oxygen during boiler shutdown conditions. Results are described in the final technical report.

46 CFR 61.05-10 - Boilers in service.

Science.gov (United States)

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Boilers in service. 61.05-10 Section 61.05-10 Shipping... INSPECTIONS Tests and Inspections of Boilers § 61.05-10 Boilers in service. (a) Each boiler, including superheater, reheater, economizer, auxiliary boiler, low-pressure heating boiler, and unfired steam boiler...

Analysis of Boiler Operational Variables Prior to Tube Leakage Fault by Artificial Intelligent System

Directory of Open Access Journals (Sweden)

Al-Kayiem Hussain H.

2014-07-01

Full Text Available Steam boilers are considered as a core of any steam power plant. Boilers are subjected to various types of trips leading to shut down of the entire plant. The tube leakage is the worse among the common boiler faults, where the shutdown period lasts for around four to five days. This paper describes the rules of the Artificial Intelligent Systems to diagnosis the boiler variables prior to tube leakage occurrence. An Intelligent system based on Artificial Neural Network was designed and coded in MATLAB environment. The ANN was trained and validated using real site data acquired from coal fired power plant in Malaysia. Ninety three boiler operational variables were identified for the present investigation based on the plant operator experience. Various neural networks topology combinations were investigated. The results showed that the NN with two hidden layers performed better than one hidden layer using Levenberg-Maquardt training algorithm. Moreover, it was noticed that hyperbolic tangent function for input and output nodes performed better than other activation function types.

Increased combustion stability in modulating biomass boilers for district heating systems

Energy Technology Data Exchange (ETDEWEB)

Eriksson, Gunnar; Hermansson, Roger (eds.) [Lulea Univ. of Technology (Sweden)

2002-09-01

One of the problems in small district heating systems is the large load variation that must be handled by the system. If the boiler is designed to cover the needs during the coldest day in winter time in northern Europe it would have to run at loads as low as 10% of full load during summer time, when heat is needed only for tap water production. Load variations in small networks are quite fast and earlier investigations have shown that existing biomass boilers give rise to large amounts of harmful emissions at fast load variations and at low loads. The problem has been addressed in different ways: Three new boiler concepts have been realized and tested: A prototype of a 500 kW boiler with partitioned primary combustion chamber and supplied with a water heat store. A 10 kW bench scale combustor and a 500 kW prototype boiler based on pulsating combustion. Bench scale boilers to test the influence from applied sound on emissions and a 150 kW prototype boiler with a two-stage secondary vortex combustion chamber. Development of control and regulating equipment: Glow Guard, a control system using infra-red sensors to detect glowing char on the grate, has been constructed and tested. A fast prediction model that can be used in control systems has been developed. Simulation of the combustion process: Code to simulate pyrolysis/gasification of fuel on the grate has been developed. Combustion of the gas phase inside the combustion chamber has been simulated. The two models have been combined to describe the combustion process inside the primary chamber of a prototype boiler. A fast simulation code based on statistical methods that can predict the environmental performance of boilers has been developed. One of the boiler concepts matches the desired load span from 10 to 100% of full load with emissions far below the set limits for CO and THC and close to the set limits for NO{sub x}. The other boilers had a bit more narrow load range, one with very low emissions except for NO

Numerical simulations of the industrial circulating fluidized bed boiler under air- and oxy-fuel combustion

International Nuclear Information System (INIS)

Adamczyk, Wojciech P.; Kozołub, Paweł; Klimanek, Adam; Białecki, Ryszard A.; Andrzejczyk, Marek; Klajny, Marcin

2015-01-01

Measured and numerical results of air-fuel combustion process within large scale industrial circulating fluidized bed (CFB) boiler is presented in this paper. For numerical simulations the industrial compact CFB boiler was selected. Numerical simulations were carried out using three-dimensional model where the dense particulate transport phenomenon was simultaneously modelled with combustion process. The fluidization process was modelled using the hybrid Euler-Lagrange approach. The impact of the geometrical model simplification on predicted mass distribution and temperature profiles over CFB boiler combustion chamber two kinds of geometrical models were used, namely the complete model which consist of combustion chamber, solid separators, external solid super-heaters and simplified boiler geometry which was reduced to the combustion chamber. The evaluated temperature and pressure profiles during numerical simulations were compared against measured data collected during boiler air-fuel operation. Collected data was also used for validating numerical model of the oxy-fuel combustion model. Stability of the model and its sensitivity on changes of several input parameters were studied. The comparison of the pressure and temperature profiles for all considered cases gave comparable trends in contrary to measured data. Moreover, some additional test was carried out the check the influence of radiative heat transfer on predicted temperature profile within the CFB boiler. - Highlights: • Hybrid Euler-Lagrange approach was used for modelling particle transport, air- and oxy-fuel combustion process. • Numerical results were validated against measured data. • The influence of different boiler operating conditions on calculated temperature profile was investigated. • New strategy for resolving particle transport in circulating fluidized bed was shown

Economic aspects of reducing SO2 emissions of medium power boilers

International Nuclear Information System (INIS)

Kartak, J.

1995-01-01

The results of analysis of the economic benefits of five reconstruction variants are presented for a hypothetical industrial heating plant equipped with 3 boilers with a steam output of 120 t/h each, providing a total power of about 355 MW. The reconstruction was aimed at reducing the emission of pollutants to below the regulatory limits. The economic effectiveness was assessed in terms of the specific cost of heat in overheated steam for brown coal, black coal, natural gas, and mazut. The option consisting in reconstruction of the brown coal fired boiler to low-sulfur black coal without desulfurization emerged as the economically optimal alternative. Second to it was the option identical with the first but augmented with a dry additive desulfurization equipment. The brown coal fired boiler equipped with a semidry desulfurization equipment ranked as the third. (J.B.). 3 tabs., 6 figs

Exergy analysis on industrial boiler energy conservation and emission evaluation applications

Science.gov (United States)

Li, Henan

2017-06-01

Industrial boiler is one of the most energy-consuming equipments in china, the annual consumption of energy accounts for about one-third of the national energy consumption. Industrial boilers in service at present have several severe problems such as small capacity, low efficiency, high energy consumption and causing severe pollution on environment. In recent years, our country in the big scope, long time serious fog weather, with coal-fired industrial boilers is closely related to the regional characteristics of high strength and low emissions [1]. The energy-efficient and emission-reducing of industry boiler is of great significance to improve China’s energy usage efficiency and environmental protection. Difference in thermal equilibrium theory is widely used in boiler design, exergy analysis method is established on the basis of the first law and second law of thermodynamics, by studying the cycle of the effect of energy conversion and utilization, to analyze its influencing factors, to reveal the exergy loss of location, distribution and size, find out the weak links, and a method of mining system of the boiler energy saving potential. Exergy analysis method is used for layer combustion boiler efficiency and pollutant emission characteristics analysis and evaluation, and can more objectively and accurately the energy conserving potential of the mining system of the boiler, find out the weak link of energy consumption, and improve equipment performance to improve the industrial boiler environmental friendliness.

Maintenance of immersion ultrasonic testing on the water tube boiler

International Nuclear Information System (INIS)

Ishiyama, Toru; Kawasaki, Ichio; Miura, Hirohito

2014-01-01

There are 4-boiler in nuclear fuel cycle engineering laboratories (NCL). These boilers have been operated in the long term over 20 years. One of them, the leakage of boiler water was found at one of the generating tubes, and 2 adjoining generating tubes were corroded in Dec, 2011. These generating tubes were investigated by immersion ultrasonic testing (UT) for measure thickness of the tube. As a result, thinner tube was found in a part of a bend and near the water drum. These parts are covered with sulfide deposit, it seems that the generating tubes were corroded by sulfide. (author)

Charting the boiler market

International Nuclear Information System (INIS)

2003-01-01

The ''boiler market'' of electricity, sometimes called unsecured transmission, is electric power consumption that in public statistics is restricted by the obligation of the customers to cut their consumption at short notice and therefore are granted some discount on the network lease. The present document is part of a project that aims to provide a better understanding of the flexibility in the Norwegian power market, limited by the power-intensive industry and the boiler market. It discusses the boiler market. It begins with a discusses of the available statistics, where different sources show very dissimilar consumption figures. Then it examines how the consumption in the boiler market developed during the winter 2002/2003. Finally, there is a description of the regulations of unsecured transmission and how the various network owners adapt to the regulations.

Questions about the reliability of recovery boilers of steel smelting units

Energy Technology Data Exchange (ETDEWEB)

Sazykin, Yu K; Mukhametzyanov, N K

1979-01-01

Because the main reason for failure of recovery boilers is contamination of the heating surfaces, the operational conditions of individual elements of boiler units, equipped with vibrational and pulsed cleaning are analyzed and the reliability of the cleaning systems in use today is evaluated. The recovery boilers from open hearth furnaces and two bath steel smelting units from the Magnitogorsk Metallurgic Combine were selected as the subjects of the study. It is established that the boiler heating surface cleaning system has a quite large number of failures. The vibrational cleaning readiness factor is rated at 0.9323 and that of the pulsed cleaning system, 0.9698. For the KU-100 recovery boilers with a mean productivity of 18-20 t/h, the losses caused by failures during operation with vibration and pulsed cleaning were 3,200 and 1,700 rubles per year, respectively. With reconstruction of the boilers, which is associated with an increase in their reliability, the vibration cleaning of the heating surface was replaced by pulsed cleaning.

Linear modeling of nonlinear systems using artificial neural networks based on I/O data and its application in power plant boiler modeling

International Nuclear Information System (INIS)

Ghaffari, A.; Nikkhah Bahrami, M.; Mohammadzaheri, M.

2005-01-01

In this paper a new method for linear modeling of nonlinear systems is presented. The method is based on the design of an artificial neural network with two layers. The network is trained only according to the input-output data of the system. The weights of connections in this network, represents the coefficients of the transfer function. For systems with linear behavior the method of least square error represents the best linear model of the system. However, for nonlinear systems, such as some subsystems in power plants boilers LSE does not represent the best linear approximation of the system, necessarily. In this paper a new linear modeling method is presented and applied to some subsystems in a power plant boiler. Comparison between the transfer function obtained in this way and by least square error method,shows that the neural network method gives better linear models for these nonlinear systems

Monitoring energy efficiency of condensing boilers via hybrid first-principle modelling and estimation

NARCIS (Netherlands)

Satyavada, Harish; Baldi, S.

2018-01-01

The operating principle of condensing boilers is based on exploiting heat from flue gases to pre-heat cold water at the inlet of the boiler: by condensing into liquid form, flue gases recover their latent heat of vaporization, leading to 10–12% increased efficiency with respect to traditional

Coal utilization in industrial boilers in China - a prospect for mitigating CO2 emissions

International Nuclear Information System (INIS)

Fang, J.; Zeng, T.; Yang, L.I.S.; Oye, K.A.; Sarofim, A.F.; Beer, J.M.

1999-01-01

It is estimated from GEF statistical data for 1991 that more than 500,000 industrial boilers (mostly stoker-fired) in China consume over 400 million tons of coal per year. Each year, because of low boiler efficiency, 75 million tons of coal is wasted and 130 million tons of excess CO 2 are emitted. An analysis of 250 boiler thermal-balance test certificates and 6 field visits in three provinces have shown that: (1) boilers with efficiencies of less than 70% account for 75% of the total boiler-population; (2) the main causes of the low efficiencies are high excess air and unburned carbon in the slag and fly ash. The effect of unburned carbon on CO 2 emission is a balance of positive and negative contributions: while the unburned carbon does not produce CO 2 emissions, its replacement carbon, burned at a low efficiency, contributes to a net increase in CO 2 emissions. It seems from the analysis that the average boiler efficiency can be raised to 73% by relatively simple means, such as the size grading of the coal, improved boiler operating practice and some inexpensive equipment modifications. This could then result in savings each year of 34 million tons of coal and a reduction in CO 2 emissions of 63 million tons at an estimated cost of $10 per ton of CO 2 . (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

Model-Based Water Wall Fault Detection and Diagnosis of FBC Boiler Using Strong Tracking Filter

Directory of Open Access Journals (Sweden)

Li Sun

2014-01-01

Full Text Available Fluidized bed combustion (FBC boilers have received increasing attention in recent decades. The erosion issue on the water wall is one of the most common and serious faults for FBC boilers. Unlike direct measurement of tube thickness used by ultrasonic methods, the wastage of water wall is reconsidered equally as the variation of the overall heat transfer coefficient in the furnace. In this paper, a model-based approach is presented to estimate internal states and heat transfer coefficient dually from the noisy measurable outputs. The estimated parameter is compared with the normal value. Then the modified Bayesian algorithm is adopted for fault detection and diagnosis (FDD. The simulation results demonstrate that the approach is feasible and effective.

Recovery Act: Oxy-Combustion Techology Development for Industrial-Scale Boiler Applications

Energy Technology Data Exchange (ETDEWEB)

Levasseur, Armand

2014-04-30

matrix of fuels, oxyprocess variables and boiler design parameters. Significant improvement of CFD modeling tools and validation against 15 MWth experimental data has been completed. Oxy-boiler demonstration and large reference designs have been developed, supported with the information and knowledge gained from the 15 MWth testing. The results from the 15 MWth testing in the BSF and complimentary bench-scale testing are addressed in this volume (Volume II) of the final report. The results of the modeling efforts (Volume III) and the oxy boiler design efforts (Volume IV) are reported in separate volumes.

Environmental performance assessment of utility boiler energy conversion systems

International Nuclear Information System (INIS)

Li, Changchun; Gillum, Craig; Toupin, Kevin; Park, Young Ho; Donaldson, Burl

2016-01-01

Highlights: • Sustainability analyses of utility boilers are performed. • Natural gas fired boilers have the least CO_2 emissions in fossil fueled boilers. • Solar boilers rank last with an emergy yield ratio of 1.2. • Biomass boilers have the best emergy sustainability index. - Abstract: A significant amount of global electric power generation is produced from the combustion of fossil fuels. Steam boilers are one of the most important components for steam and electricity production. The objective of this paper is to establish a theoretical framework for the sustainability analysis of a utility boiler. These analyses can be used by decision-makers to diagnose and optimize the sustainability of a utility boiler. Seven utility boiler systems are analyzed using energy and embodied solar energy (emergy) principles in order to evaluate their environmental efficiencies. They include a subcritical coal fired boiler, a supercritical coal fired boiler, an oil fired boiler, a natural gas fired boiler, a concentrating solar power boiler utilizing a tower configuration, a biomass boiler, and a refuse derived fuel boiler. Their relative environmental impacts were compared. The results show that the natural gas boiler has significantly lower CO_2 emission than an equivalent coal or oil fired boiler. The refuse derived fuel boiler has about the same CO_2 emissions as the natural gas boiler. The emergy sustainability index of a utility boiler system is determined as the measure of its sustainability from an environmental perspective. Our analyses results indicate that the natural gas boiler has a relatively high emergy sustainability index compared to other fossil fuel boilers. Converting existing coal boilers to natural gas boilers is a feasible option to achieve better sustainability. The results also show that the biomass boiler has the best emergy sustainability index and it will remain a means to utilize the renewable energy within the Rankine steam cycle. Before

Characterization of Oxy-combustion Impacts in Existing Coal-fired Boilers

Energy Technology Data Exchange (ETDEWEB)

Bradley Adams; Andrew Fry; Constance Senior; Hong Shim; Huafeng Wang; Jost Wendt; Christopher Shaddix

2009-06-30

This report summarizes Year 1 results of a research program designed to use multi-scale experimental studies and fundamental theoretical models to characterize and predict the impacts of retrofit of existing coal-fired utility boilers for oxy-combustion. Through the course of Year 1 activities, great progress was made toward understanding the issues associated with oxy-combustion retrofit of coal-fired boilers. All four Year 1 milestones and objectives have been, or will be, completed on schedule and within budget. Progress in the four milestone areas may be summarized as follows: • University of Utah has performed size segregated ash composition measurements in the Oxy-Fuel Combustor (OFC). These experiments indicate that oxy-combustion retrofit may impact ash aerosol mineral matter composition. Both flame temperature and flue gas composition have been observed to influence the concentration of calcium, magnesium and iron in the fine particulate. This could in turn impact boiler fouling and slagging. • Sandia National Labs has shown that char oxidation rate is dependent on particle size (for sizes between 60 and 100 microns) by performing fundamental simulations of reacting char particles. These predictions will be verified by making time-resolved optical measurements of char particle temperature, velocity and size in bench-scale experiments before the end of Year 1. • REI and Siemens have completed the design of an oxy-research burner that will be mounted on University of Utah’s pilot-scale furnace, the L1500. This burner will accommodate a wide range of O2, FGR and mixing strategies under conditions relevant for utility boiler operation. Through CFD modeling of the different burner designs, it was determined that the key factor influencing flame stabilization location is particle heat-up rate. The new oxy-research burner and associated equipment is scheduled for delivery before the end of Year 1. • REI has completed a literature survey of slagging and

Developing trends with boiler operation and management

Energy Technology Data Exchange (ETDEWEB)

Stark, J.M. [Occupational Safety and Health Service, Wellington (New Zealand). Dept. of Labour, Engineering Safety Branch

1993-12-31

Over recent years there have been many improvements in boiler control and safety management systems. Technology has made major advances and is now regarded as being well proven in Australia, Europe and the United Kingdom and these changes have been examined by a project committee, convened for the purpose, to establish whether they are equally applicable in New Zealand. The result of the committee`s findings and experience is contained in the `Draft Code of Practice`. This paper explains the development of the `Code of Practice`, the reasoning behind some of the decisions taken and the implications of these changes to boiler owners.

Techno-economic analysis of wood biomass boilers for the greenhouse industry

International Nuclear Information System (INIS)

Chau, J.; Sowlati, T.; Sokhansanj, S.; Preto, F.; Melin, S.; Bi, X.

2009-01-01

The objective of this study is to perform a techno-economic analysis on a typical wood pellet and wood residue boiler for generation of heat to an average-sized greenhouse in British Columbia. The variables analyzed included greenhouse size and structure, boiler efficiency, fuel types, and source of carbon dioxide (CO 2 ) for crop fertilization. The net present value (NPV) show that installing a wood pellet or a wood residue boiler to provide 40% of the annual heat demand is more economical than using a natural gas boiler to provide all the heat at a discount rate of 10%. For an assumed lifespan of 25 years, a wood pellet boiler system could generate NPV of C$259,311 without electrostatic precipitator (ESP) and C$74,695 with ESP, respectively. While, installing a wood residue boiler with or without an ESP could provide NPV of C$919,922 or C$1,104,538, respectively. Using a wood biomass boiler could also eliminate over 3000 tonne CO 2 equivalents of greenhouse gases annually. Wood biomass combustion generates more particulate matters than natural gas combustion. However, an advanced emission control system could significantly reduce particulate matters emission from wood biomass combustion which would bring the particulate emission to a relatively similar level as for natural gas

1995 Annual Report and Five Year (1995-1999) Strategic Investment Plan

Science.gov (United States)

1996-08-01

IPPD IRP ISB IUSS rvD JATO JETCs JHUAPL JPL LAAP LAMS LANL LARPS LCA LCAAP LIBS LIF LIN LLNL LMS LNAPL LOVA LRS&T MADOM...Actual Funding FY94 $(K) Boiler/Engine Emissions Metal Perovskite Catalysts for NOx Reduction (AF) 175 Steady-State/Nonsteady-State Nox Emission...Funding FY95 $(K) Boiler/Engine Emissions Evaluation of Metal Perovskite Catalysts for NOx Reduction (AF) 25 Compact, Closed-Loop Controlled Waste

A study by simulation of dynamic instability in boilers using the NUMEL/DYMEL suite of programmes

International Nuclear Information System (INIS)

Jeffries, T.O.

1985-01-01

Tube-to-tube instability in a once through sodium heated boiler has been studied using the finite difference model developed by the CEGB and embodied in the NUMEL and DYMEL compute codes. The method used was to simulate the boiler and then carry out frequency response tests, as one would on a real boiler. The advantages of using the simulation model compared with using the real system are the ease with which experiments may be performed and the ease of access to a wide range of parameters which could only be obtained approximately, if at all, from a real boiler. The advantage is that validation of the model is only approximate though in the case of sodium heated boilers, conditions are similar to those in electrically heated rigs used for validation. The study led to an understanding of how such a boiler should be operated to avoid tube-to-tube instability and with the detailed temperature profiles available from NUMEL it was possible to develop existing theory to predict boiler transfer functions similar to those observed in the frequency response tests. (author)

Economical analyses of construction of a biomass boiler house

International Nuclear Information System (INIS)

Normak, A.

2002-01-01

To reduce the energy costs we can use cheaper fuel to fire our boiler. One of the cheapest fuels is wood biomass. It is very actual issue how to use cheaper wood biomass in heat generation to decrease energy costs and to increase biomass share in our energy balance. Before we decide to build biomass boiler house it is recommendable to analyse the economical situation and work out most profitable, efficient, reliable and ecological boiler plant design on particular conditions. The best way to perform the analyses is to use the economical model presented. It saves our time and gives objective evaluation to the project. (author)

Fuel quality and its effect on the design of power boilers in the USA

Energy Technology Data Exchange (ETDEWEB)

Kotler, V.R.

1984-05-01

Statistical data, taken from Power, Proceedings of the American Power Conference and others, on developments since the 1950s in boiler design caused by the increasing use of lower quality fuel (subbituminous and lignite coals) are presented. The effect of pollution regulations in the USA on boiler design is discussed. The results of a 16 year study by the TVA on the decrease in coal quality fired in its boilers and its effect on boiler efficiency are presented. Methods of transport are surveyed. Descriptions and characteristics of several modern boilers designed by Babcock and Wilcox, Combustion Engineering, Foster-Wheeler and Riley Stoker are given. 13 references.

Maximising safety in the boiler house.

Science.gov (United States)

Derry, Carr

2013-03-01

Last month's HEJ featured an article, the second in our new series of guidance pieces aimed principally at Technician-level engineers, highlighting some of the key steps that boiler operators can take to maximise system performance and efficiency, and thus reduce running both costs and carbon footprint. In the third such article, Derry Carr, C.Env, I.Eng, BSc (Hons), M.I.Plant.E., M.S.O.E., technical manager & group gas manager at Dalkia, who is vice-chairman of the Combustion Engineering Association, examines the key regulatory and safety obligations for hospital energy managers and boiler technicians, a number of which have seen changes in recent years with revision to guidance and other documentation.

Hybrid model predictive control applied to switching control of burner load for a compact marine boiler design

DEFF Research Database (Denmark)

Solberg, Brian; Andersen, Palle; Maciejowski, Jan

2008-01-01

This paper discusses the application of hybrid model predictive control to control switching between different burner modes in a novel compact marine boiler design. A further purpose of the present work is to point out problems with finite horizon model predictive control applied to systems for w...

Control Properties of Bottom Fired Marine Boilers

DEFF Research Database (Denmark)

Solberg, Brian; Andersen, Palle; Karstensen, Claus M. S.

2005-01-01

This paper focuses on model analysis of a dynamic model of a bottom fired one-pass smoke tube boiler. Linearised versions of the model are analysed to determine how gain, time constants and right half plane zeros (caused by the shrink-and-swell phenomenon) depend on the steam flow load. Furthermore...... the interactions in the system are inspected to analyse potential benefit from using a multivariable control strategy in favour of the current strategy based on single loop theory. An analysis of the nonlinear model is carried out to further determine the nonlinear characteristics of the boiler system...... and to verify whether nonlinear control is needed. Finally a controller based on single loop theory is used to analyse if input constraints become active when rejecting transient behaviour from the disturbance steam flow. The model analysis shows large variations in system gains at steady state as function...

New controls spark boiler efficiency

Energy Technology Data Exchange (ETDEWEB)

Engels, T. (Monsanto, University Park, IL (United States))

1993-09-01

Monsanto's NutraSweet plant in University Park, IL, produces aspartame, the patented NutraSweet artificial sweetener product. Until recently, boiler control was managed by a '60s-era Fireye jackshaft system in which air and natural gas were mechanically linked with an offset to compensate for oxygen trim. The interlocking devices on the Fireye system were becoming obsolete, and the boiler needed a new front end retrofitted for low emissions. In order to improve boiler control efficiency, we decided to modernize and automate the entire boiler control system. We replaced the original jackshaft system, and installed a Gordon-Piet burner system, including gas valves, air dampers, blowers, and burner. The upgrade challenges included developing a control strategy and selecting and implementing a process control system. Since our plant has standardized on the PROVOX process management information system from Fisher Controls (now Fisher-Rosemount Systems) to support most of our process, it was a natural and logical choice for boiler controls as well. 2 figs.

40 CFR 68.42 - Five-year accident history.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Five-year accident history. 68.42... (CONTINUED) CHEMICAL ACCIDENT PREVENTION PROVISIONS Hazard Assessment § 68.42 Five-year accident history. (a) The owner or operator shall include in the five-year accident history all accidental releases from...

46 CFR 52.25-20 - Exhaust gas boilers.

Science.gov (United States)

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Exhaust gas boilers. 52.25-20 Section 52.25-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING POWER BOILERS Other Boiler Types § 52.25-20 Exhaust gas boilers. Exhaust gas boilers with a maximum allowable working pressure...

Five-Year Risk of Interval-Invasive Second Breast Cancer

Science.gov (United States)

Buist, Diana S. M.; Houssami, Nehmat; Dowling, Emily C.; Halpern, Elkan F.; Gazelle, G. Scott; Lehman, Constance D.; Henderson, Louise M.; Hubbard, Rebecca A.

2015-01-01

Background: Earlier detection of second breast cancers after primary breast cancer (PBC) treatment improves survival, yet mammography is less accurate in women with prior breast cancer. The purpose of this study was to examine women presenting clinically with second breast cancers after negative surveillance mammography (interval cancers), and to estimate the five-year risk of interval-invasive second cancers for women with varying risk profiles. Methods: We evaluated a prospective cohort of 15 114 women with 47 717 surveillance mammograms diagnosed with stage 0-II unilateral PBC from 1996 through 2008 at facilities in the Breast Cancer Surveillance Consortium. We used discrete time survival models to estimate the association between odds of an interval-invasive second breast cancer and candidate predictors, including demographic, PBC, and imaging characteristics. All statistical tests were two-sided. Results: The cumulative incidence of second breast cancers after five years was 54.4 per 1000 women, with 325 surveillance-detected and 138 interval-invasive second breast cancers. The five-year risk of interval-invasive second cancer for women with referent category characteristics was 0.60%. For women with the most and least favorable profiles, the five-year risk ranged from 0.07% to 6.11%. Multivariable modeling identified grade II PBC (odds ratio [OR] = 1.95, 95% confidence interval [CI] = 1.15 to 3.31), treatment with lumpectomy without radiation (OR = 3.27, 95% CI = 1.91 to 5.62), interval PBC presentation (OR = 2.01, 95% CI 1.28 to 3.16), and heterogeneously dense breasts on mammography (OR = 1.54, 95% CI = 1.01 to 2.36) as independent predictors of interval-invasive second breast cancers. Conclusions: PBC diagnosis and treatment characteristics contribute to variation in subsequent-interval second breast cancer risk. Consideration of these factors may be useful in developing tailored post-treatment imaging surveillance plans. PMID:25904721

New thinking for the boiler room.

Science.gov (United States)

Rose, Wayne

2008-09-01

Wayne Rose, marketing manager at integrated plant room manufacturer Armstrong Integrated Systems, explains how increasing use of off-site manufacture, the latest 3D modelling technology, and advances in control technology, are revolutionising boiler room design and construction.

Characterization of Oxy-combustion Impacts in Existing Coal-fired Boilers

Energy Technology Data Exchange (ETDEWEB)

Adams, Bradley [Univ. of Utah, Salt Lake City, UT (United States); Davis, Kevin [Univ. of Utah, Salt Lake City, UT (United States); Senior, Constance [Univ. of Utah, Salt Lake City, UT (United States); Shim, Hong Shim [Univ. of Utah, Salt Lake City, UT (United States); Otten, Brydger Van [Univ. of Utah, Salt Lake City, UT (United States); Fry, Andrew [Univ. of Utah, Salt Lake City, UT (United States); Wendt, Jost [Univ. of Utah, Salt Lake City, UT (United States); Eddings, Eric [Univ. of Utah, Salt Lake City, UT (United States); Paschedag, Alan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Shaddix, Christopher [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Cox, William [Brigham Young Univ., Provo, UT (United States); Tree, Dale [Brigham Young Univ., Provo, UT (United States)

2013-09-30

Reaction Engineering International (REI) managed a team of experts from University of Utah, Siemens Energy, Praxair, Vattenfall AB, Sandia National Laboratories, Brigham Young University (BYU) and Corrosion Management Ltd. to perform multi-scale experiments, coupled with mechanism development, process modeling and CFD modeling, for both applied and fundamental investigations. The primary objective of this program was to acquire data and develop tools to characterize and predict impacts of CO{sub 2} flue gas recycle and burner feed design on flame characteristics (burnout, NO{sub x}, SO{sub x}, mercury and fine particle emissions, heat transfer) and operational concerns (fouling, slagging and corrosion) inherent in the retrofit of existing coal-fired boilers for oxy-coal combustion. Experimental work was conducted at Sandia National Laboratories’ Entrained Flow Reactor, the University of Utah Industrial Combustion Research Facility, and Brigham Young University. Process modeling and computational fluid dynamics (CFD) modeling was performed at REI. Successful completion of the project objectives resulted in the following key deliverables: 1) Multi-scale test data from 0.1 kW bench-scale, 100 kW and 200 kW laboratory-scale, and 1 MW semi-industrial scale combustors that describe differences in flame characteristics, fouling, slagging and corrosion for coal combustion under air-firing and oxygen-firing conditions, including sensitivity to oxy-burner design and flue gas recycle composition. 2) Validated mechanisms developed from test data that describe fouling, slagging, waterwall corrosion, heat transfer, char burnout and sooting under coal oxy-combustion conditions. The mechanisms were presented in a form suitable for inclusion in CFD models or process models. 3) Principles to guide design of pilot-scale and full-scale coal oxy-firing systems and flue gas recycle configurations, such that boiler operational impacts from oxy-combustion retrofits are minimized. 4

Simulation study on the maximum continuous working condition of a power plant boiler

Science.gov (United States)

Wang, Ning; Han, Jiting; Sun, Haitian; Cheng, Jiwei; Jing, Ying'ai; Li, Wenbo

2018-05-01

First of all, the boiler is briefly introduced to determine the mathematical model and the boundary conditions, then the boiler under the BMCR condition numerical simulation study, and then the BMCR operating temperature field analysis. According to the boiler actual test results and the hot BMCR condition boiler output test results, the simulation results are verified. The main conclusions are as follows: the position and size of the inscribed circle in the furnace and the furnace temperature distribution and test results under different elevation are compared and verified; Accuracy of numerical simulation results.

Ash fouling monitoring and key variables analysis for coal fired power plant boiler

Directory of Open Access Journals (Sweden)

Shi Yuanhao

2015-01-01

Full Text Available Ash deposition on heat transfer surfaces is still a significant problem in coal-fired power plant utility boilers. The effective ways to deal with this problem are accurate on-line monitoring of ash fouling and soot-blowing. In this paper, an online ash fouling monitoring model based on dynamic mass and energy balance method is developed and key variables analysis technique is introduced to study the internal behavior of soot-blowing system. In this process, artificial neural networks (ANN are used to optimize the boiler soot-blowing model and mean impact values method is utilized to determine a set of key variables. The validity of the models has been illustrated in a real case-study boiler, a 300MW Chinese power station. The results on same real plant data show that both models have good prediction accuracy, while the ANN model II has less input parameters. This work will be the basis of a future development in order to control and optimize the soot-blowing of the coal-fired power plant utility boilers.

Identification of boiler tube leak in PHWR by measuring short lived radioisotope Iodine-134 in boiler water using gamma spectrometric techniques

International Nuclear Information System (INIS)

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

2015-01-01

The boiler tube made up of Monel-400 of RAPS-2 has failed on few occasions. Due to the failure of boiler tube, the active heavy water enters into boiler and feed water leading to contamination of radioactivity in secondary water circuit. The identification of boiler tube failure was done by measuring gamma ray activity of Iodine-134 in the boiler water with sample using gamma spectrometry with high purity germanium detector. In order to increase the sensitivity of the method 5 liters of Boiler water sample was passed through a plastic column containing 40 ml of anion resin and 10 ml of activated charcoal to capture the isotopes of Iodine in the anionic form and molecular form. Samples were collected from all 8 Boilers of RAPS-2. The activity of 134 I was shown only by Boiler - 5. No other boilers showed any activity of 134 I. This indicated that Boiler - 5 had leaky tubes. The leaky hairpin of boiler - 5 was identified by measuring Tritium and IP in the riser and down comer of all 10 HXs. On the basis of Tritium and IP result, HX-7 was identified as leaky hairpin. (author)

Co-firing of coal with biomass and waste in full-scale suspension-fired boilers

Energy Technology Data Exchange (ETDEWEB)

Dam-Johansen, Kim; Frandsen, Flemming J.; Jensen, Peter A.; Jensen, Anker D. [Technical Univ. of Denmark, Lyngby (Denmark). Dept. of chemical and Biochemical Engineering

2013-07-01

The energy policy in Denmark has for many years focused on lowering the net CO{sub 2} emission from heat and power production by replacing fossil fuels by renewable resources. This has been done by developing dedicated grate-fired boilers for biomass and waste fuels but also by developing coal-based suspension-fired boilers to accept still higher fractions of biomass or waste material as fuels. This last development has been challenging of many reasons, including pre-treatment of fuels, and solving potential emission and operational problems during the simultaneous development of supercritical steam cycles with steam temperatures close to 600 C, providing power efficiencies close to 50% (Hein KRG, Sustainable energy supply and environment protection - strategies, resources and technologies. In: Gupta R, Wall T, Hupa M, Wigley F, Tillman D, Frandsen FJ (eds) Proceedings of international conference on impact of fuel quality on power production and the environment, Banff Conference Centre, Banff, Alberta, Canada, 29 Sept-4 Oct, 2008). For 25 years the CHEC (Combustion and Harmful Emission Control) Research Centre at DTU Chemical Engineering, has attained a leading role in research, supporting power producing industry, plant owners and boiler manufacturers to optimize design and operation and minimize cost and environmental impact using alternative fuels in suspension fired boilers. Our contribution has been made via a combination of full-scale measuring campaigns, pilot-scale studies, lab-scale measurements and modeling tools. The research conducted has addressed many issues important for co-firing, i.e. fuel processing, ash induced boiler deposit formation and corrosion, boiler chamber fuel conversion and emission formation, influence on flue gas cleaning equipment and the utilization of residual products. This chapter provides an overview of research activities, aiming at increasing biomass shares during co-firing in suspension, conducted in close collaboration with

Mod increases AGR boiler output

International Nuclear Information System (INIS)

Jones, W.K.C.; Rider, G.; Taylor, D.E.

1986-01-01

During the commissioning runs of the first reactor units at Heysham I and Hartlepool Advanced Gas-cooled Reactors (AGRs), non-uniform temperature distributions were observed across individual boiler units which were more severe than those predicted from the design analysis. This article describes the re-orificing (referruling) of the boilers to overcome this problem. The referruling has reduced boiler sensitivity and resulted in an increase of load of 7 or 8%. (U.K.)

Economic valuation of heat pumps and electric boilers in the Danish energy system

International Nuclear Information System (INIS)

Nielsen, Maria Grønnegaard; Morales, Juan Miguel; Zugno, Marco; Pedersen, Thomas Engberg; Madsen, Henrik

2016-01-01

Highlights: • We assess the economic value of heat pumps and electric boilers in Denmark. • The daily operation of a heat and power system is modeled by stochastic programming. • Deterministic models overestimate the value of heat pumps and electric boilers. • Heat pumps and electric boilers can reduce the cost of operating the Danish system. • Falling power prices may boost the future value of heat pumps and electric boilers. - Abstract: Heat pumps (HP) and electric immersion boilers (EB) have great potential to increase flexibility in energy systems. In parallel, decreasing taxes on electricity-based heat production are creating a more favorable economic environment for the deployment of these units in Denmark. In this paper, the economic value of heat pumps and electric boilers is assessed by simulating their day-to-day market performance using a novel operational strategy based on two-stage stochastic programming. This stochastic model is employed to optimize jointly the daily operation of HPs and EBs along with the Combined Heat and Power (CHP) units in the system. Uncertainty in the heat demand and power price is modeled via scenarios representing different plausible paths for their future evolution. A series of case-studies are performed using real-world data for the heat and power systems in the Copenhagen area during four representative weeks of 2013. We show that the use of stochastic operational models is critical, as standard deterministic models provide an overestimation of the added benefits from the installation of HPs and EBs, thus leading to over-investment in capacity. Furthermore, we perform sensitivity studies to investigate the effect on market performance of varying capacity and efficiency for these units, as well as of different levels of prices in the electricity market. We find that these parameters substantially affect the profitability of heat pumps and electric boilers, hence, they must be carefully assessed by potential

Control Properties of Bottom Fired Marine Boilers

DEFF Research Database (Denmark)

Solberg, Brian; Andersen, Palle; Karstensen, Claus M. S.

2007-01-01

This paper focuses on model analysis of a dynamic model of a bottom fired one-pass smoke tube boiler. Linearized versions of the model are analyzed and show large variations in system gains at steady state as function of load whereas gain variations near the desired bandwidth are small. An analys...

System of optimization computations of five year plans in the coal industry. [USSR

Energy Technology Data Exchange (ETDEWEB)

Goyzman, E I; Korenev, V G

1980-01-01

A system of optimization computations of five year plans is set forth which was developed over a number of years at the Central Scientific Research Institute of Economics and Scientific-Technical Information of the Coal Industry. Basic principles of design and methodological approaches are given which were used in development of the systemas well as levels of administration and information links between them. The report analyzes the characteristics of problems of planning which arise at different stages of formation of the five year plans and discusses possibilities of taking into account these characteristics in optimized models. Economic formulations of problems of optimization of five year plans are given as applied to two levels of administration: at the branch level and at the level of production associations. Economic-mathematical models of optimization of five year plans are developed for each of the levels and their characteristic features described. The primary methodological principles, on the basis of which optimization models were developed are examined. An economic-mathematical model with continuous variables was developed for the branch level of planning. Volumes of recovery according to a group of shafts in the stage of normal operation (stable group) of each production enterprise are adopted as model variables. A system of limitations which includes limitations on volumes and distinguishable resources is formulated. The minimum of operating expenses, minimum of capital investments and maximum of recovery volumes for the planned period can be used as the optimization criteria. An economic-mathematical model which uses integral variable was developed for the production association level.

Simulation of pulverized coal fired boiler: reaction chamber

Energy Technology Data Exchange (ETDEWEB)

Rodrigues, C.P.; Lansarin, M.A.; Secchi, A.R.; Mendes, T.F. [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Dept. de Engenharia Quimica. Grupo de Modelagem, Simulacao, Controle e Otimizacao de Processos)]. E-mail: {cperdomo, marla, arge, talita}@enq.ufrgs.br

2005-06-15

This work is part of a joint project to built a computational tool for power plant simulation, dealing specifically with the reaction chamber (place of the boiler where the fuel is burned). In order to describe the conversion of chemical energy to thermal energy, an one dimensional pseudo-homogeneous mathematical model, with variable physical properties, and based on mass and energy balances, was developed. The equations were implemented in the gPROMS simulator and the model parameters were estimated using the module gEST of this software, with experimental data from a large-scale coal-fired utility boiler and kinetic data from the open literature. The results showed that the model predicts the composition of the outlet combustion gas satisfactorily. (author)

The 2010 five-yearly review has started

CERN Multimedia

Association du personnel

2009-01-01

Every five years, the financial and social conditions of members of the personnel are examined according to the procedures defined in Annex A1 of the Staff Rules and Regulations (SR&R). This exercise is called the “five-yearly review” (5YR).

Failure Analysis of 600 MW Supercritical Boiler Water Wall

OpenAIRE

Fu Huilin; Cai Zhengchun; Yan Xiaozhong; He Jinqiao; Zhou Yucai

2013-01-01

Boiler tube often causes abnormal boiler outage, bringing greater economic losses. This thesis mainly comes from the dynamics of boiler water, boiler furnace accident location of wall temperature distribution to explore the cause of the accident boiler. Calculation results show that the deformation will seriously reduce the boiler allowable maximum temperature difference between the screens. And the boiler is not over-temperature, low temperature difference between the screens, which have bur...

Catalytic burners in larger boiler appliances

Energy Technology Data Exchange (ETDEWEB)

Silversand, Fredrik; Persson, Mikael (Catator AB, Lund (Sweden))

2009-02-15

This project focuses on the scale up of a Catator's catalytic burner technology to enable retrofit installation in existing boilers and the design of new innovative combinations of catalytic burners and boilers. Different design approaches are discussed and evaluated in the report and suggestions are made concerning scale-up. Preliminary test data, extracted from a large boiler installation are discussed together with an accurate analysis of technical possibilities following an optimization of the boiler design to benefit from the advantages of catalytic combustion. The experimental work was conducted in close collaboration with ICI Caldaie (ICI), located in Verona, Italy. ICI is a leading European boiler manufacturer in the effect segment ranging from about 20 kWt to several MWt. The study shows that it is possibly to scale up the burner technology and to maintain low emissions. The boilers used in the study were designed around conventional combustion and were consequently not optimized for implementation of catalytic burners. From previous experiences it stands clear that the furnace volume can be dramatically decreased when applying catalytic combustion. In flame combustion, this volume is normally dimensioned to avoid flame impingement on cold surfaces and to facilitate completion of the gas-phase reactions. The emissions of nitrogen oxides can be reduced by decreasing the residence time in the furnace. Even with the over-dimensioned furnace used in this study, we easily reached emission values close to 35 mg/kWh. The emissions of carbon monoxide and unburned hydrocarbons were negligible (less than 5 ppmv). It is possible to decrease the emissions of nitrogen oxides further by designing the furnace/boiler around the catalytic burner, as suggested in the report. Simultaneously, the size of the boiler installation can be reduced greatly, which also will result in material savings, i.e. the production cost can be reduced. It is suggested to optimize the

Inception report and gap analysis. Boiler inspection

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-06-01

This inception and gap analysis report on boilers in Latvia, has been prepared in the framework of the 'Implementation of the EU directive on energy performance of buildings: development of the Latvian Scheme for energy auditing of building and inspection of boilers'. The report is the basis for the establishment of training of boiler inspectors; it develops a gap analysis for better understanding and estimating the number of installations in Latvia and develops suggestions for the institutional set up. In particular includes information on existing standard and regulation on boiler, suggestion for the content of the training material of experts for boiler inspections and a syllabus of the training course. A specific section is dedicated to the suggestion for certification system of trained boiler inspectors. (au)

Optimal Switching Control of Burner Setting for a Compact Marine Boiler Design

DEFF Research Database (Denmark)

Solberg, Brian; Andersen, Palle; Maciejowski, Jan M.

2010-01-01

This paper discusses optimal control strategies for switching between different burner modes in a novel compact  marine boiler design. The ideal behaviour is defined in a performance index the minimisation of which defines an ideal trade-off between deviations in boiler pressure and water level...... approach is based on a generalisation of hysteresis control. The strategies are verified on a simulation model of the compact marine boiler for control of low/high burner load switches.  ...

Deposit Probe Measurements in Large Biomass-Fired Grate Boilers and Pulverized-Fuel Boilers

DEFF Research Database (Denmark)

Hansen, Stine Broholm; Jensen, Peter Arendt; Jappe Frandsen, Flemming

2014-01-01

A number of full-scale deposit probe measuring campaigns conducted in grate-fired and suspension-fired boilers, fired with biomass, have been reviewed and compared. The influence of operational parameters on the chemistry of ash and deposits, on deposit build-up rates, and on shedding behavior has...... of the deposits formed is determined by the fly ash composition and the flue gas temperature; increases in the local flue gas temperature lead to higher contents of Si and Ca and lower contents of Cl in the deposits. The net deposit build-up rates in grate-fired and suspension-fired boilers are at similar levels....../wood-firing in suspension-fired boilers, shedding occurred by debonding with incomplete removal at flue gas temperatures of 600–1000 °C and by debonding with complete removal during wood-firing in suspension-fired boilers at high flue gas temperatures (1300 °C). Shedding events were not observed during wood suspension...

Practical Validation of Economic Efficiency Modelling Method for Multi-Boiler Heating System

Directory of Open Access Journals (Sweden)

Aleksejs Jurenoks

2017-12-01

Full Text Available In up-to-date conditions information technology is frequently associated with the modelling process, using computer technology as well as information networks. Statistical modelling is one of the most widespread methods of research of economic systems. The selection of methods of modelling of the economic systems depends on a great number of conditions of the researched system. Modelling is frequently associated with the factor of uncertainty (or risk, who’s description goes outside the confines of the traditional statistical modelling, which, in its turn, complicates the modelling which, in its turn, complicates the modelling process. This article describes the modelling process of assessing the economic efficiency of a multi-boiler adaptive heating system in real-time systems which allows for dynamic change in the operation scenarios of system service installations while enhancing the economic efficiency of the system in consideration.

Experimental investigation of stresses and deformations of the model of a pod-boiler-prestressed concrete pressure vessel. Pt. 1

International Nuclear Information System (INIS)

Stoever, R.

1973-01-01

Investigations of elastic models are suitable to obtain independent values for stress states and deformations of thickwalled pressure vessels to check computer programs for three-dimensional elastic calculations. An elastic model of epoxy resin was constructed with the geometry of the pod boiler pressure vessel of the Hartlepool nuclear power station. With this model strains and deformations were measured for internal pressure. The stress states in the neighbourhood of the large vertical openings for the boiler pods and the horizontal gas ducts and at the junction of cylinder and plates were of special interest. Therefore most of the gauges were concentrated in these regions. A considerable number of strain gauges were embedded in the wall. The construction of the model is described in part one and results of the measurements are presented and discussed in part two of this report. (orig.) [de

Estimation of Scale Deposition in the Water Walls of an Operating Indian Coal Fired Boiler: Predictive Modeling Approach Using Artificial Neural Networks

Science.gov (United States)

Kumari, Amrita; Das, Suchandan Kumar; Srivastava, Prem Kumar

2016-04-01

Application of computational intelligence for predicting industrial processes has been in extensive use in various industrial sectors including power sector industry. An ANN model using multi-layer perceptron philosophy has been proposed in this paper to predict the deposition behaviors of oxide scale on waterwall tubes of a coal fired boiler. The input parameters comprises of boiler water chemistry and associated operating parameters, such as, pH, alkalinity, total dissolved solids, specific conductivity, iron and dissolved oxygen concentration of the feed water and local heat flux on boiler tube. An efficient gradient based network optimization algorithm has been employed to minimize neural predictions errors. Effects of heat flux, iron content, pH and the concentrations of total dissolved solids in feed water and other operating variables on the scale deposition behavior have been studied. It has been observed that heat flux, iron content and pH of the feed water have a relatively prime influence on the rate of oxide scale deposition in water walls of an Indian boiler. Reasonably good agreement between ANN model predictions and the measured values of oxide scale deposition rate has been observed which is corroborated by the regression fit between these values.

FY 2000 report on the survey project on potentiality of the environmental harmony coal utilization system. Potential study of the circulating fluidized bed boiler model project in Vietnam; 2000 nendo kankyo chowagata sekitan riyo system kanosei chosa jigyo hokokusho. Vietnam ni okeru junkan ryudosho boiler model jigyo jisshi kanosei chosa

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-03-01

In Vietnam, survey was conducted of the project in which the adoption of circulating fluidized bed boiler (CFB) makes energy conservation and greenhouse effect gas reduction possible. CFB makes a marked decrease in SOx emission possible by using limestone as combustion bed material. As a result of the survey, the thermal power plant was not suitable for the model project due to its large size. However, it was found that two cement plants and one fiber plant having coal-fired boiler were suitable for survey. Nghi Son and Bim Son cement plants are typical cement plants in Vietnam. As a result of the hearing, they were eager to adopt CFB equipment. As to environmental improvement effects, in the thermal power plant with power source loads, emissions of SOx and NOx can be reduced by 79.0% and 72.5%, respectively. Further, in Nam Dinh Textile Company, emissions of SOx and NOx can be reduced by 79.8% and 84.6%, respectively, in case of converting boiler from the existing stoker boiler to CFB boiler. (NEDO)

CFD simulation of the combustion process of the low-emission vortex boiler

Science.gov (United States)

Chernov, A. A.; Maryandyshev, P. A.; Pankratov, E. V.; Lubov, V. K.

2017-11-01

Domestic heat and power engineering needs means and methods for optimizing the existing boiler plants in order to increase their technical, economic and environmental work. The development of modern computer technology, methods of numerical modeling and specialized software greatly facilitates the solution of many emerging problems. CFD simulation allows to obtaine precise results of thermochemical and aerodynamic processes taking place in the furnace of boilers in order to optimize their operation modes and develop directions for their modernization. The paper presents the results of simulation of the combustion process of a low-emission vortex coal boiler of the model E-220/100 using the software package Ansys Fluent. A hexahedral grid with a number of 2 million cells was constructed for the chosen boiler model. A stationary problem with a two-phase flow was solved. The gaseous components are air, combustion products and volatile substances. The solid phase is coal particles at different burnup stages. The Euler-Lagrange approach was taken as a basis. Calculation of the coal particles trajectories was carried out using the Discrete Phase Model which distribution of the size particle of coal dust was accounted for using the Rosin-Rammler equation. Partially Premixed combustion model was used as the combustion model which take into account elemental composition of the fuel and heat analysis. To take turbulence into account, a two-parameter k-ε model with a standard wall function was chosen. Heat transfer by radiation was calculated using the P1-approximation of the method of spherical harmonics. The system of spatial equations was numerically solved by the control volume method using the SIMPLE algorithm of Patankar and Spaulding. Comparison of data obtained during the industrial-operational tests of low-emission vortex boilers with the results of mathematical modeling showed acceptable convergence of the tasks of this level, which confirms the adequacy of the

Inception report and gap analysis. Boiler inspection

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-06-01

This inception and gap analysis report on boilers in Latvia, has been prepared in the framework of the 'Implementation of the EU directive on energy performance of buildings: development of the Latvian Scheme for energy auditing of building and inspection of boilers'. The report is the basis for the establishment of training of boiler inspectors; it develops a gap analysis for better understanding and estimating the number of installations in Latvia and develops suggestions for the institutional set up. In particular includes information on existing standard and regulation on boiler, suggestion for the content of the training material of experts for boiler inspections and a syllabus of the training course. A specific section is dedicated to the suggestion for certification system of trained boiler inspectors. (au)

Research report for fiscal 1998. Basic research for promoting joint implementation, etc. (master plan for changing district heating boilers, Nizhniy Novgorod province); 1998 nendo chosa hokokusho. Nizhniy Novgorod shu chiiki danboyo boiler tenkan master plan

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

The above-named plan aims to reduce greenhouse gas emissions and enhance energy efficiency. The above-named Russian system for supplying heat and hot water is operated by the 51 local governments in the province, with boiler houses sited at 4047 locations. Almost all of them are approximately 30 years old, low in thermal efficiency because of their obsolete design and structure, costly because of their old parts and components wanting repair, and higher in fuel cost than those fired by natural gas. It is indispensable to replace the existing boilers with natural gas-fired boilers, and it is estimated that there are 4511 boilers that require such replacement. When the heat supply business operated by the local governments is modernized, the CO2 gas emission will be reduced by approximately 2.675-million tons/year. As for energy efficiency, it is found that replacement by heavy oil-fired boilers is the highest in terms of the effect of investment. (NEDO)

Oil fired boiler/solar tank- and natural gas burner/solar tank-units

DEFF Research Database (Denmark)

Furbo, Simon; Vejen, Niels Kristian; Frederiksen, Karsten Vinkler

1999-01-01

During the last few years new units consisting of a solar tank and either an oil fired boiler or a natural gas burner have been introduced on the Danish market. Three different marketed units - two based on a natural gas burner and one based on an oil fired boiler - have been tested in a heat...

Early tube leak detection system for steam boiler at KEV power plant

Directory of Open Access Journals (Sweden)

Ismail Firas B.

2016-01-01

Full Text Available Tube leakage in boilers has been a major contribution to trips which eventually leads to power plant shut downs. Training of network and developing artificial neural network (ANN models are essential in fault detection in critically large systems. This research focusses on the ANN modelling through training and validation of real data acquired from a sub-critical boiler unit. The artificial neural network (ANN was used to develop a compatible model and to evaluate the working properties and behaviour of boiler. The training and validation of real data has been applied using the feed-forward with back-propagation (BP. The right combination of number of neurons, number of hidden layers, training algorithms and training functions was run to achieve the best ANN model with lowest error. The ANN was trained and validated using real site data acquired from a coal fired power plant in Malaysia. The results showed that the Neural Network (NN with one hidden layers performed better than two hidden layer using feed-forward back-propagation network. The outcome from this study give us the best ANN model which eventually allows for early detection of boiler tube leakages, and forecast of a trip before the real shutdown. This will eventually reduce shutdowns in power plants.

Numerical simulation of a 374 tons/h water-tube steam boiler following a feedwater line break

International Nuclear Information System (INIS)

Deghal Cheridi, Amina Lyria; Chaker, Abla; Loubar, Ahcène

2016-01-01

Highlights: • We simulate the behavior of a steam boiler during feed-water line break accident. • To perform accident analysis of the steam boiler, Relap5/Mod3.2 system code is used. • A Relap5 model of the boiler is developed and qualified at the steady state level. • A good agreement between Relap5 results and available experimental data. • The Relap5 model predicts well the main transient features of the boiler. - Abstract: To ensure the operational safety of an industrial water-tube steam boiler it is very important to assess various accident scenarios in real plant working conditions. One of the most challenging scenarios is the loss of feedwater to the steam boiler. In this paper, a simulation of the behavior of an industrial water-tube radiant steam boiler during feedwater line break accident is discussed. The simulation is carried out using the RELAP5 system code. The steam boiler is installed in an Algerian natural gas liquefaction complex. The simulation shows the capabilities of RELAP5 system code in predicting the behavior of the steam boiler at both steady state and transient working conditions. From another side, the behavior of the steam boiler following the accident shows how the control system can successfully mitigate the effects and consequences of such accident and how the evaporator tubes can undergo a severe damage due to an uncontrolled increase of the wall temperature in case of failure of this system.

Environmental restoration and waste management five year plan, fiscal years 1994--1998

International Nuclear Information System (INIS)

1993-01-01

In March 1989, Secretary of Energy James D. Watkins outlined his vision for a changed Department of Energy (DOE) culture. This culture is one of envirorunental responsibility, increased knowledge and involvement in environmental management, a new openness to public input, and overall accountability to the Nation for its actions. Secretary Watkins also requested all the near-term activities necessary to bring DOEactivities into compliance with all applicable environmental requirements to be detailed in one plan. The Five-Year Plan was to be based on a ''bottom up'' approach to planning by using Activity Data Sheets to collect financial and technical information at the installation level. Over the past three years, the Five-Year Plan has evolved into the primary planning tool for the DOE Environmental Restoration and Waste Management Program, looking beyond the current three-year Federal budget horizon. The FY 1994--1998 Five-Year Plan demonstrates DOE's commitment to a culture based on the principles of openness, responsiveness, and accountability; reports on the progress made in carrying out DOE's environmental mission; identifies what must be accomplished during a five-year planning period; and describes strategies for achieving critical program objectives. This plan represents another step towards the implementation of the culture change Secretary Watkins envisioned. The Five-Year Plan is not exclusively focused on near-term activities. Italso expresses the DOE commitment to a 30-year goal for the cleanup of the 1989 inventory of inactive sites. The FY 1994--1998 Five-Year Plan reiterates the DOE commitment to meeting this and other important environmental goals

49 CFR 230.30 - Lap-joint seam boilers.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Lap-joint seam boilers. 230.30 Section 230.30..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Inspection and Repair § 230.30 Lap-joint seam boilers. Every boiler having lap-joint longitudinal seams...

A CFD study on the dust behaviour in a metallurgical waste-heat boiler

Energy Technology Data Exchange (ETDEWEB)

Yongxiang, Yang; Jokilaakso, A [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Materials Processing and Powder Metallurgy

1998-12-31

A waste-heat boiler forms an essential part for the treatment of high temperature flue-gases in most metallurgical processes. Flue-dust carried by the furnace off-gas has to be captured efficiently in the waste-heat boilers before entering the downstream gas purification equipment. Flue dust may accumulate and foul on the heat transfer surfaces such as tube-walls, narrow conjunctions between the boiler and the furnace uptake, and thus may cause smelter shutdown, and interrupt the production. A commercial CFD package is used as the major tool on modelling the dust flow and settling in the waste-heat boiler of an industrial copper flash smelter. In the presentation, dust settling behaviour is illustrated for a wide range of particle sizes, and dust capture efficiency in the radiation section of the boiler for different particle sizes has been shown with the transient simulation. The simulation aims at providing detailed information of dust behaviour in the waste-heat boiler in sulphide smelting. (author) 11 refs.

A CFD study on the dust behaviour in a metallurgical waste-heat boiler

Energy Technology Data Exchange (ETDEWEB)

Yang Yongxiang; Jokilaakso, A. [Helsinki Univ. of Technology, Otaniemi (Finland). Lab. of Materials Processing and Powder Metallurgy

1997-12-31

A waste-heat boiler forms an essential part for the treatment of high temperature flue-gases in most metallurgical processes. Flue-dust carried by the furnace off-gas has to be captured efficiently in the waste-heat boilers before entering the downstream gas purification equipment. Flue dust may accumulate and foul on the heat transfer surfaces such as tube-walls, narrow conjunctions between the boiler and the furnace uptake, and thus may cause smelter shutdown, and interrupt the production. A commercial CFD package is used as the major tool on modelling the dust flow and settling in the waste-heat boiler of an industrial copper flash smelter. In the presentation, dust settling behaviour is illustrated for a wide range of particle sizes, and dust capture efficiency in the radiation section of the boiler for different particle sizes has been shown with the transient simulation. The simulation aims at providing detailed information of dust behaviour in the waste-heat boiler in sulphide smelting. (author) 11 refs.

The pressure cold wind system on the impact of industrial boiler economy and security

Science.gov (United States)

Li, Henan; Qian, Hongli; Jiang, Lei; Yu, Dekai; Li, Guannan; Yuan, Hong

2017-05-01

Industrial boiler is one of the most energy-consuming equipment in china, the annual consumption of energy accounts for about one-third of the national energy consumption.Industrial boiler in service at present have several severe problems such as small capacity, low efficiency, high energy consumption and causing severe pollution on environment, the average industrial boiler operation efficiency is only 65%. If the efficiency increased by 15% ∼ 20%, which meet the international advanced level, each year 70 million tons of coal saving and reduce environmental pollution[1]. As energy conservation and emissions reduction becomes the basic national policy of our country, improving the efficiency of industrial boiler energy is facing opportunities and challenges, optimizing the operation mode of the existing units, it is necessary to increase the flexibility of the boiler control.

Factors affecting stress assisted corrosion cracking of carbon steel under industrial boiler conditions

Science.gov (United States)

Yang, Dong

Failure of carbon steel boiler tubes from waterside has been reported in the utility boilers and industrial boilers for a long time. In industrial boilers, most waterside tube cracks are found near heavy attachment welds on the outer surface and are typically blunt, with multiple bulbous features indicating a discontinuous growth. These types of tube failures are typically referred to as stress assisted corrosion (SAC). For recovery boilers in the pulp and paper industry, these failures are particularly important as any water leak inside the furnace can potentially lead to smelt-water explosion. Metal properties, environmental variables, and stress conditions are the major factors influencing SAC crack initation and propagation in carbon steel boiler tubes. Slow strain rate tests (SSRT) were conducted under boiler water conditions to study the effect of temperature, oxygen level, and stress conditions on crack initation and propagation on SA-210 carbon steel samples machined out of boiler tubes. Heat treatments were also performed to develop various grain size and carbon content on carbon steel samples, and SSRTs were conducted on these samples to examine the effect of microstructure features on SAC cracking. Mechanisms of SAC crack initation and propagation were proposed and validated based on interrupted slow strain tests (ISSRT). Water chemistry guidelines are provided to prevent SAC and fracture mechanics model is developed to predict SAC failure on industrial boiler tubes.

Failure analysis of boiler tube

International Nuclear Information System (INIS)

Mehmood, K.; Siddiqui, A.R.

2007-01-01

Boiler tubes are energy conversion components where heat energy is used to convert water into high pressure superheated steam, which is then delivered to a turbine for electric power generation in thermal power plants or to run plant and machineries in a process or manufacturing industry. It was reported that one of the tubes of a fire-tube boiler used in a local industry had leakage after the formation of pits at the external surface of the tube. The inner side of the fire tube was working with hot flue gasses with a pressure of 10 Kg/cm/sup 2/ and temperature 225 degree C. The outside of the tube was surrounded by feed water. The purpose of this study was to determine the cause of pits developed at the external surface of the failed boiler tube sample. In the present work boiler tube samples of steel grade ASTM AI61/ASTM A192 were analyzed using metallographic analysis, chemical analysis, and mechanical testing. It was concluded that the appearance of defects on the boiler tube sample indicates cavitation type corrosion failure. Cavitation damage superficially resembled pitting, but surface appeared considerably rougher and had many closely spaced pits. (author)

The Effect of Talking Drawings on Five-Year-Old Turkish Children's Mental Models of the Water Cycle

Science.gov (United States)

Ahi, Berat

2017-01-01

The purpose of the current study is to determine the effect of talking drawings on Turkish preschool children's mental models of the water cycle. The study was conducted in the city of Kastamonu, located in the north-west of Turkey. A total of 40 five-year-old preschool children participated in the study in the spring term of the 2015-2016 school…

Life extension of boilers using weld overlay protection

Energy Technology Data Exchange (ETDEWEB)

Lai, G; Hulsizer, P [Welding Services Inc., Norcross, GA (United States); Brooks, R [Welding Services Inc., Welding Services Europe, Spijkenisse (Netherlands)

1999-12-31

The presentation describes the status of modern weld overlay technology for refurbishment, upgrading and life extension of boilers. The approaches to life extension of boilers include field overlay application, shop-fabricated panels for replacement of the worn, corroded waterwall and shop-fabricated overlay tubing for replacement of individual tubes in superheaters, generating banks and other areas. The characteristics of weld overlay products are briefly described. Also discussed are successful applications of various corrosion-resistant overlays for life extension of boiler tubes in waste-to-energy boilers, coal-fired boilers and chemical recovery boilers. Types of corrosion and selection of weld overlay alloys in these systems are also discussed. (orig.) 14 refs.

Life extension of boilers using weld overlay protection

Energy Technology Data Exchange (ETDEWEB)

Lai, G.; Hulsizer, P. [Welding Services Inc., Norcross, GA (United States); Brooks, R. [Welding Services Inc., Welding Services Europe, Spijkenisse (Netherlands)

1998-12-31

The presentation describes the status of modern weld overlay technology for refurbishment, upgrading and life extension of boilers. The approaches to life extension of boilers include field overlay application, shop-fabricated panels for replacement of the worn, corroded waterwall and shop-fabricated overlay tubing for replacement of individual tubes in superheaters, generating banks and other areas. The characteristics of weld overlay products are briefly described. Also discussed are successful applications of various corrosion-resistant overlays for life extension of boiler tubes in waste-to-energy boilers, coal-fired boilers and chemical recovery boilers. Types of corrosion and selection of weld overlay alloys in these systems are also discussed. (orig.) 14 refs.

Assessing the impact of primary measures for NOx reduction on the thermal power plant steam boiler

International Nuclear Information System (INIS)

Stupar, Goran; Tucaković, Dragan; Živanović, Titoslav; Belošević, Srdjan

2015-01-01

The European normatives prescribe content of 200 mg/Nm 3 NO x for pulverized coal combusting power plants. In order to reduce content of NO x in Serbian thermal power plant (TPP) 'Kostolac B' it's necessary to implement particular measures until 2016. The mathematical model of lignite combustion in the steam boiler furnace is defined and applied to analyze the possibility of implementing certain primary measures for reducing nitrogen oxides and their effects on the steam boiler operation. This model includes processes in the coal-fired furnace and defines radiating reactive two-phase turbulent flow. The model of turbulent flow also contains sub-model of fuel and thermal NO x formation and destruction. This complex mathematical model is related to thermal and aerodynamic calculations of the steam boiler within a unified calculation system in order to analyze the steam boiler overall work. This system provides calculations with a number of influential parameters. The steam boiler calculations for unit 1 (350 MWe) of TPP 'Kostolac B' are implemented for existing and modified combustion system in order to achieve effective, reliable and ecological facility work. The paper presents the influence analysis of large number of parameters on the steam boiler operation with an accepted concept of primary measures. Presented system of calculations is verified against measurements in TPP 'Kostolac B'. - Highlights: • Modern steam boilers need to operate according to ecological standards. • Possibility of applying some of the primary measures of NO x reduction. • Conventional calculations have no possibility to estimate sub-stoichiometric combustion. • Develop a new method of connecting the calculations. • Analysis shows the most favorable operation boiler regime (efficiency and ecology)

The 2015 five-yearly review

CERN Multimedia

Staff Association

2014-01-01

  This year CERN celebrates its 60th anniversary. On this occasion, throughout Europe — most recently on July 1st at the UNESCO headquarters in Paris — festivities are being organized to celebrate the Organization’s success as a flagship laboratory of high-energy physics. To ensure that CERN can remain a centre of excellence in the field of fundamental research, the Organization verifies every five years with the help of a five-yearly review procedure whether the financial and social conditions which it proposes to Staff Members allow it to recruit and retain Staff Members of the highest competence and integrity required for the execution of its mission from all its Member States. For Fellows these conditions should remain attractive compared with those in comparable research institutions, while for Associated members of personnel these conditions should allow it to host them in its research facilities taking into account the highest cost-of-living level in the local ...

46 CFR 63.25-7 - Exhaust gas boilers.

Science.gov (United States)

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Exhaust gas boilers. 63.25-7 Section 63.25-7 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING AUTOMATIC AUXILIARY BOILERS Requirements for Specific Types of Automatic Auxiliary Boilers § 63.25-7 Exhaust gas boilers. (a) Construction...

Five-year risk of interval-invasive second breast cancer.

Science.gov (United States)

Lee, Janie M; Buist, Diana S M; Houssami, Nehmat; Dowling, Emily C; Halpern, Elkan F; Gazelle, G Scott; Lehman, Constance D; Henderson, Louise M; Hubbard, Rebecca A

2015-07-01

Earlier detection of second breast cancers after primary breast cancer (PBC) treatment improves survival, yet mammography is less accurate in women with prior breast cancer. The purpose of this study was to examine women presenting clinically with second breast cancers after negative surveillance mammography (interval cancers), and to estimate the five-year risk of interval-invasive second cancers for women with varying risk profiles. We evaluated a prospective cohort of 15 114 women with 47 717 surveillance mammograms diagnosed with stage 0-II unilateral PBC from 1996 through 2008 at facilities in the Breast Cancer Surveillance Consortium. We used discrete time survival models to estimate the association between odds of an interval-invasive second breast cancer and candidate predictors, including demographic, PBC, and imaging characteristics. All statistical tests were two-sided. The cumulative incidence of second breast cancers after five years was 54.4 per 1000 women, with 325 surveillance-detected and 138 interval-invasive second breast cancers. The five-year risk of interval-invasive second cancer for women with referent category characteristics was 0.60%. For women with the most and least favorable profiles, the five-year risk ranged from 0.07% to 6.11%. Multivariable modeling identified grade II PBC (odds ratio [OR] = 1.95, 95% confidence interval [CI] = 1.15 to 3.31), treatment with lumpectomy without radiation (OR = 3.27, 95% CI = 1.91 to 5.62), interval PBC presentation (OR = 2.01, 95% CI 1.28 to 3.16), and heterogeneously dense breasts on mammography (OR = 1.54, 95% CI = 1.01 to 2.36) as independent predictors of interval-invasive second breast cancers. PBC diagnosis and treatment characteristics contribute to variation in subsequent-interval second breast cancer risk. Consideration of these factors may be useful in developing tailored post-treatment imaging surveillance plans. © The Author 2015. Published by Oxford University Press. All rights reserved

Engineering bed models for solid fuel conversion process in grate-fired boilers

DEFF Research Database (Denmark)

Costa, M.; Massarotti, N.; Indrizzi, V.

2014-01-01

of the syngas predicted by the two models is equal to about 7%. The application to different types of biomass shows that the difference in the predictions increases as the carbon content grows. The phenomenological model, in fact, generally considers higher conversion rates of this element to volatiles......A comparison between two numerical models describing the thermo-chemical conversion process of a solid fuel bed in a grate-fired boiler is presented. Both models consider the incoming biomass as subjected to drying, pyrolysis, gasification and combustion. In the first approach the biomass bed...... is treated as a 0D system, where the thermo-chemical processes are divided in two successive sections: drying and conversion. Phenomenological laws are written to characterize the syngas release as a function of the main governing parameters. The second model is an empirical 1D approach. Temperature, species...

[Combustion zone investigation and modelling in fuel flexible suspension fired boilers]. Result summary and status

Energy Technology Data Exchange (ETDEWEB)

Lovmand Hvid, S.

2011-12-15

The project has been designed to obtain data from a power plant boiler with co-combustion, partly to gain greater knowledge of particle turnover in the fuel zone, partly to support the development of modeling tools. Data collection occurred at Studstrup Power Station Unit 4, where the fuel is a combination of coal and biomass. The boiler is equipped with 24 dust burners, four of which have been converted to firing with biomass. Measurements have been carried out in the flame zone with different fuels: coal alone, coal + straw and coal + wood. During the experiments velocity fields, temperature fields and gas concentration fields were measured in the firing zone. Also, particle samples from the flame zone ware collected. Several measurements are performed with well-known techniques, but in addition, the project developed new optical measurement methods based on UV spectroscopy. They allow measuring other gases than the hitherto known methods and allow you to gain insight into the dynamic variations beyond just mean fields. The collection of particle samples from the boiler was, as expected, a very challenging task under the given conditions, but was carried out with a largely satisfactory result. Analysis of the samples has initially failed to lead to an increased recognition of the speed of the conversion process, but the samples will be analyzed in more detail in other projects. (LN)

46 CFR 63.25-1 - Small automatic auxiliary boilers.

Science.gov (United States)

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Small automatic auxiliary boilers. 63.25-1 Section 63.25... AUXILIARY BOILERS Requirements for Specific Types of Automatic Auxiliary Boilers § 63.25-1 Small automatic auxiliary boilers. Small automatic auxiliary boilers defined as having heat-input ratings of 400,000 Btu/hr...

Bio boiler - Control conditions. Part 1: Model development and analysis of operating conditions; Biokedel - Reguleringsmaessige forhold. Del 1: Modeludvikling og analyse af dynamiske driftsforhold

Energy Technology Data Exchange (ETDEWEB)

Boecher Poulsen, K.; Christensen, Torkild; Mortensen, Jan; Runge Kristoffersen, J.; Kristmundsson, E. [Tech-wise A/S (Denmark); Moekbak, T.; Mortensen, Hans Peter [Elsam A/S (Denmark)

2002-12-15

This report focuses on the model-building part of the PSO project, 'Control Conditions Bio-boiler'. In the project, which treats dynamic simulation of biomass fired power plants via the MMS software, a certain number of straw/wood chip modules have been built, together with a combustion module which, when connected to the existing MMS modules, can be used for dynamic simulation. Furthermore, a certain number of continuous and discrete components have been built which, together with the remaining MMS modules will create a complete model of the active part of the control structure under the most common operation conditions. By means of the developed straw, combustion and control modules, a model of Enstedvaerket's bio-boiler is built (without wood chip super-heater), including practically all auxiliary control mechanisms. In the report the primary problems caused by the development of the model are discussed, typically numerical problems. First of all it is discussed how a steady state condition can be reached from a nonphysical condition at the start-up of the simulation. After reaching a steady state condition at full load, the boiler load is reduced by adjusting the desired live steam flow setpoint value and the load gradient (as it would be done from the control room). While reducing to part load, one straw line is closed down, as it would be done in 'real life'. From part load, the boiler load is once again in the same way increased to full. (BA) The simulation results are then compared to measurements made on the same boiler during load reduction and load increase.

Recovery Act: Oxy-Combustion Technology Development for Industrial-Scale Boiler Applications. Task 4 - Testing in Alstom's 15 MW_th Boiler Simulation Facility

Energy Technology Data Exchange (ETDEWEB)

Levasseur, Armand

2014-04-30

fuels, oxy-process variables and boiler design parameters. Significant improvement of CFD modeling tools and validation against 15 MWth experimental data has been completed. Oxy-boiler demonstration and large reference designs have been developed, supported with the information and knowledge gained from the 15 MWth testing. This report addresses the results from the 15 MWth testing in the BSF.

Environmental restoration and waste management five-year plan, Fiscal years 1994--1998

International Nuclear Information System (INIS)

1993-01-01

In March 1989, Secretary of Energy James D. Watkins outlined his vision for a changed Department of Energy (DOE) culture. This culture is one of environmental responsibility, increased knowledge and involvement in environmental management, a new openness to public input, and overall accountability to the Nation for its actions. Over the past three years, the Five Year Plan has evolved into the primary planning tool for the DOE Environmental Restoration and Waste Management Program, looking beyond the current three-year Federal budget horizon. The FY 1994--1998 Five-Year Plan demonstrates DOE's commitment to a culture based on the principles of openness, responsiveness, and accountability; reports on the progress made in carrying out DOE's environmental mission; identifies what must be accomplished during a five-year planning period; and describes strategies for achieving critical program objectives. The Five-Year Plan is not exclusively focused on near-term activities. It also expresses the DOE commitment to a 30-year goal for the cleanup of the 1989 inventory of inactive sites. This goal was established in response to recommendations from the State and Tribal Government Working Group (STGWG) that DOE define a specific end point for completing necessary remediation and restoration activities. The FY 1994--1998 Five-Year Plan reiterates the DOE commitment to meeting this and other important environmental goals

Burnout of pulverized biomass particles in large scale boiler – Single particle model approach

DEFF Research Database (Denmark)

Saastamoinen, Jaakko; Aho, Martti; Moilanen, Antero

2010-01-01

the particle combustion model is coupled with one-dimensional equation of motion of the particle, is applied for the calculation of the burnout in the boiler. The particle size of biomass can be much larger than that of coal to reach complete burnout due to lower density and greater reactivity. The burner...... location and the trajectories of the particles might be optimised to maximise the residence time and burnout....

Final stage of first super-critical 460 MW CFB boiler construction. First experience

Energy Technology Data Exchange (ETDEWEB)

Ostrowski, Waldemar [PKE, Lagisza Power Plant (Poland); Goral, Damian [Foster Wheeler Energia Polska, Sosnowiec (Poland)

2010-07-01

Steam boilers with circulating fluidised bed combustion have been advanced in the past years and proved well as large-scale technology. A further step was the development and construction of a boiler with super-critical steam parameters and increased output. In 2002 the Polish utility Poludniowy Koncern Energetyczny SA awarded a contract to Foster Wheeler Energia Oy to erect a fluidised bed boiler for the Lagisza power plant. Construction of the 460 MW plant was started in 2006. The plant has been in commercial operation since 2009. (orig.)

Computational fluid dynamic simulations of coal-fired utility boilers: An engineering tool

Energy Technology Data Exchange (ETDEWEB)

Efim Korytnyi; Roman Saveliev; Miron Perelman; Boris Chudnovsky; Ezra Bar-Ziv [Ben-Gurion University of the Negev, Beer-Sheva (Israel)

2009-01-15

The objective of this study was to develop an engineering tool by which the combustion behavior of coals in coal-fired utility boilers can be predicted. We presented in this paper that computational fluid dynamic (CFD) codes can successfully predict performance of - and emission from - full-scale pulverized-coal utility boilers of various types, provided that the model parameters required for the simulation are properly chosen and validated. For that purpose we developed a methodology combining measurements in a 50 kW pilot-scale test facility with CFD simulations using the same CFD code configured for both test and full-scale furnaces. In this method model parameters of the coal processes are extracted and validated. This paper presents the importance of the validation of the model parameters which are used in CFD codes. Our results show very good fit of CFD simulations with various parameters measured in a test furnace and several types of utility boilers. The results of this study demonstrate the viability of the present methodology as an effective tool for optimization coal burning in full-scale utility boilers. 41 refs., 9 figs., 3 tabs.

EFFICIENCY IMPROVEMENT IN INDUSTRIAL BOILER BY FLUE GAS DUCT INSULATION

OpenAIRE

Sanjay H. Zala

2017-01-01

Now a days in industry major losses are find out so here we calculate these losses and find out efficiency of boiler. Boiler efficiency and energy losses from boiler are important parameter for any industry using boiler. In this work a detailed analysis was carried out for boiler at Anish Chemicals Bhavnagar. It is a combined water and fire tube boiler using biomass coal as fuel. Boiler efficiency calculated by direct method is in range of (78.5% to 81.6%). Major losses from boiler are heat ...

Advanced technique for computing fuel combustion properties in pulverized-fuel fired boilers

Energy Technology Data Exchange (ETDEWEB)

Kotler, V.R. (Vsesoyuznyi Teplotekhnicheskii Institut (Russian Federation))

1992-03-01

Reviews foreign technical reports on advanced techniques for computing fuel combustion properties in pulverized-fuel fired boilers and analyzes a technique developed by Combustion Engineering, Inc. (USA). Characteristics of 25 fuel types, including 19 grades of coal, are listed along with a diagram of an installation with a drop tube furnace. Characteristics include burn-out intensity curves obtained using thermogravimetric analysis for high-volatile bituminous, semi-bituminous and coking coal. The patented LFP-SKM mathematical model is used to model combustion of a particular fuel under given conditions. The model allows for fuel particle size, air surplus, load, flame height, and portion of air supplied as tertiary blast. Good agreement between computational and experimental data was observed. The method is employed in designing new boilers as well as converting operating boilers to alternative types of fuel. 3 refs.

Assessment of physical workload in boiler operations.

Science.gov (United States)

Rodrigues, Valéria Antônia Justino; Braga, Camila Soares; Campos, Julio César Costa; Souza, Amaury Paulo de; Minette, Luciano José; Sensato, Guilherme Luciano; Moraes, Angelo Casali de; Silva, Emília Pio da

2012-01-01

The use of boiler wood-fired is fairly common equipment utilized in steam generation for energy production in small industries. The boiler activities are considered dangerous and heavy, mainly due to risks of explosions and the lack of mechanization of the process. This study assessed the burden of physical labor that operators of boilers are subjected during the workday. Assessment of these conditions was carried out through quantitative and qualitative measurements. A heart rate monitor, a wet-bulb globe thermometer (WBGT), a tape-measure and a digital infrared camera were the instruments used to collect the quantitative data. The Nordic Questionnaire and the Painful Areas Diagram were used to relate the health problems of the boiler operator with activity. With study, was concluded that the boiler activity may cause pains in the body of intensity different, muscle fatigue and diseases due to excessive weight and the exposure to heat. The research contributed to improve the boiler operator's workplace and working conditions.

Electrical design requirements for electrode boilers for nuclear plants

International Nuclear Information System (INIS)

Kempker, M.J.

1979-01-01

Medium-voltage steam electrode boilers, in the 20- to 50-MW range, have become an attractive alternative to comparable fossil-fueled boilers as a source of auxiliary steam during the startup and normal shutdown of nuclear power plants. The electrode boiler represents a favorable option because of environmental, fire protection, and licensing considerations. However, this electrical option brings some difficult design problems for which solutions are required in order to integrate the electrode boiler into the plant low resistance grounded power system. These considerations include the effects of an unbalanced electrode boiler on the performance of polyphase induction motors, boiler grounding for personnel safety, boiler neutral grounding, and ground relaying

Five-year-old historian.

Science.gov (United States)

Morrison, Wynne

2017-12-01

In this poem, the author describes a doctor talking with a five-year-old child who has been brought to the hospital after being in a car accident with his/her mother and brother. The child is not able to remember the mother's name, but the doctor continues to talk with the child. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Experimental verification of the scaling laws for CFB boilers of different designs

Directory of Open Access Journals (Sweden)

Mirek Paweł

2016-06-01

Full Text Available In the paper flow dynamic similarity criteria have been presented to reflect the macroscopic flow pattern in the combustion chamber of large-scale circulating fluidised bed boilers. The proposed scaling rules have been verified on two cold models of CFB boilers operating in Tauron Wytwarzanie S.A. - El. Lagisza division (scale factor 1/20 and Fortum Power and Heat Poland Sp. z o. o. Czestochowa division (scale factor 1/10 – working with the power of 966 MWth and 120 MWth, respectively. As follows from the results of measurements, regardless of CFB boiler’s geometry the use of a defined set of criterial numbers allows to obtain satisfactory agreement between the suspension density distributions registered in the CFB boilers and scaling models.

Modeling N2O Reduction and Decomposition in a Circulating Fluidized bed Boiler

DEFF Research Database (Denmark)

Johnsson, Jan Erik; Åmand, Lars-Erik; Dam-Johansen, Kim

1996-01-01

The N2O concentration was measured in a circulating fluidized bed boiler of commercial size. Kinetics for N2O reduction by char and catalytic reduction and decomposition over bed material from the combustor were determined in a laboratory fixed bed reactor. The destruction rate of N2O in the comb......The N2O concentration was measured in a circulating fluidized bed boiler of commercial size. Kinetics for N2O reduction by char and catalytic reduction and decomposition over bed material from the combustor were determined in a laboratory fixed bed reactor. The destruction rate of N2O...... in the combustion chamber and the cyclone was calculated taking three mechanisms into account: Reduction by char, catalytic decomposition over bed material and thermal decomposition. The calculated destruction rate was in good agreement with the measured destruction of N2O injected at different levels in the boiler...

Bed models for solid fuel conversion process in grate-fired boilers

DEFF Research Database (Denmark)

Costa, M.; Massarotti, N.; Indrizzi, V.

2013-01-01

-chemical processes are divided in two successive sections: drying and conversion (which includes pyrolysis, gasification and combustion). The second model is an empirical 1D approach. The two models need input data such as composition, temperature and feeding rate of biomass and primary air. Temperature, species...... to describe the thermo-chemical conversion process of a solid fuel bed in a grate-fired boiler is presented. In this work both models consider the incoming solid fuel as subjected to drying, pyrolysis, gasification and combustion. In the first approach the biomass bed is treated as a 0D system, but the thermo...... concentrations and velocity of the producer gas leaving the fuel bed provided by the two models are compared. A sensitivity analysis with respect to mass flow rate of the primary air is also performed, as well as a further comparison regarding the dependence of the producer gas properties on the initial moisture...

40 CFR 761.71 - High efficiency boilers.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false High efficiency boilers. 761.71... PROHIBITIONS Storage and Disposal § 761.71 High efficiency boilers. (a) To burn mineral oil dielectric fluid containing a PCB concentration of ≥50 ppm, but boiler shall comply with the following...

Slagging and fouling evaluation of PC-fired boilers using AshPro{sup SM}

Energy Technology Data Exchange (ETDEWEB)

Ma, Zhanhua; Iman, Felicia; Lu, Pisi [SmartBurn, LLC, Madison, WI (United States)

2013-07-01

SmartBurn {sup registered} applied AshPro{sup SM} model to two 512 MW Tangential-fired (T-fired) boilers firing US western sub- bituminous coals to evaluate the boiler slagging behaviors with different operating conditions and OFA. The boiler convective pass fouling behaviors with three different coals were also evaluated. The slagging evaluation results indicate that the OFA configuration and air flow distribution have dramatically impacts on the ash impaction rates and slagging patterns on the furnace walls. Deposit growth and strength vary at the different regions of the furnace walls. The fouling evaluation reveals that the tube bank configuration, the amount of incoming ash, the profiles of flue gas temperature, velocity, and species all have significant impacts on fouling deposit formation, growth, and strength development. In addition, the varying ash particle sizes and chemical compositions from different coals also play important roles on the fouling deposit strength development and removal. The investigation demonstrated that AshPro{sup SM} model can be used to evaluate localized slagging and fouling problems that are related to specific boiler configuration and operating conditions. It can be used to identify the major causes of ash deposition and can guide changes in boiler operation.

CFB boilers in multifuel application

International Nuclear Information System (INIS)

Goral, D.; Krzton, B.

2007-01-01

Fuel flexibility characteristic for CFB boilers plays an important rule in industrial and utility size applications. Possibility to use wider range of fuels that has been long time considered as by-products or wastes and possibility to design boilers able to operate with alternative fuels is an important factor that improves fuel delivery security and plant economy. Presented article is based on similar publications that present Foster Wheeler's experience in design and delivery of the CFB boilers for wide range of coals and cofiring by- products of crude oil refining and coal processing. Aspects of biomass cofiring will be also presented. (author)

46 CFR 61.05-20 - Boiler safety valves.

Science.gov (United States)

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Boiler safety valves. 61.05-20 Section 61.05-20 Shipping... INSPECTIONS Tests and Inspections of Boilers § 61.05-20 Boiler safety valves. Each safety valve for a drum, superheater, or reheater of a boiler shall be tested at the interval specified by table 61.05-10. [CGD 95-028...

Field Test of Boiler Primary Loop Temperature Controller

Energy Technology Data Exchange (ETDEWEB)

Glanville, P. [Partnership for Advanced Residential Retrofit, Des Plaines, IL (United States); Rowley, P. [Partnership for Advanced Residential Retrofit, Des Plaines, IL (United States); Schroeder, D. [Partnership for Advanced Residential Retrofit, Des Plaines, IL (United States); Brand, L. [Partnership for Advanced Residential Retrofit, Des Plaines, IL (United States)

2014-09-01

Beyond these initial system efficiency upgrades are an emerging class of Advanced Load Monitoring (ALM) aftermarket controllers that dynamically respond to the boiler load, with claims of 10% to 30% of fuel savings over a heating season. For hydronic boilers specifically, these devices perform load monitoring, with continuous measurement of supply and, in some cases, return water temperatures. Energy savings from these ALM controllers are derived from dynamic management of the boiler differential, where a microprocessor with memory of past boiler cycles prevents the boiler from firing for a period of time, to limit cycling losses and inefficient operation during perceived low load conditions. These differ from OTR controllers, which vary boiler setpoint temperatures with ambient conditions while maintaining a fixed differential.

Optimizing the Integrated Design of Boilers - Simulation

DEFF Research Database (Denmark)

Sørensen, K.; Karstensen, C.; Condra, T.

2004-01-01

Boilers can be considered as consisting of three main components: (i) the pressure part, (ii) the burner and (iii) the control system. To be able to develop the boilers of the future (i.e. the boilers with the lowest emissions, the highest efciency, the best dynamic performance etc.) it is import...

Sustainable development: five structural milestones for the next five-year term

International Nuclear Information System (INIS)

Demailly, Damien; Treyer, Sebastien; Levai, David; Laurans, Yann; Rochette, Julien

2017-05-01

The energy transition, climate change, biodiversity, agriculture... the French President, the government and the new majority appointed by the 2017 elections will need to make some important decisions about sustainable development over the next five-year term. Their agenda will be marked in particular by five key events, not only in France, but also at the European and international levels. These five events will be opportunities to adapt the French economy to the major challenges of the 21. century, those of a regulated globalization, combining prosperity, social protection and environmental protection

On-line monitoring system for utility boiler diagnostics

International Nuclear Information System (INIS)

Radovanovic, P.M.; Afgan, N.H.; Caralho, M.G.

1997-01-01

The paper deals with the new developed modular type Monitoring System for Utility Boiler Diagnostics. Each module is intended to assess the specific process and can be used as a stand alone application. Four modules are developed, namely: LTC - module for the on-line monitoring of parameters related to the life-time consumption of selected boiler components; TRD - module for the tube rupture detection by the position and working fluid Ieakage quantity; FAM - module for the boiler surfaces fouling (slagging) assessment and FLAP - module for visualization of the boiler furnace flame position. All four modules are tested on respective pilot plants built oil the 200 and 300 MWe utility boilers. Monitoring System is commercially available and can be realized in any combination of its modules depending on demands induced by the operational problems of specific boiler. Further development of Monitoring System is performed in accordance with the respective EU project on development of Boiler Expert System. (Author)

A novel direct-fired porous-medium boiler

Science.gov (United States)

Prasartkaew, Boonrit

2018-01-01

Nowadays, power and heat generation systems pay an important role in all economic sectors. These systems are mainly based on combustion reaction and operated under the second law of thermodynamics. A conventional boilers, a main component of heat and power generators, have thermal efficiency in the range of 70 to 85%, mainly owing to they have flue gas heat loss. This paper proposes a novel type of boiler, called a Direct-fired Porous-medium Boiler (DPB). Due to being operated without flue gas heat loss, its thermal efficiency cloud be approximately close to 100%. The steam produced from the proposed boiler; however, is not pure water steam. It is the composite gases of steam and combustion-product-gases. This paper aims at presenting the working concept and reporting the experimental results on the performance of the proposed boiler. The experiments of various operating parameters were performed and collected data were used for the performance analysis. The experimental results demonstrated that the proposed boiler can be operated as well as the conceptual design and then it is promising. It can be possibly further developed to be a high efficiency boiler by means of reducing or suppressing the surface heat loss with better insulator and/or refractory lined.

Advanced CFD modelling of air and recycled flue gas staging in a waste wood-fired grate boiler for higher combustion efficiency and greater environmental benefits.

Science.gov (United States)

Rajh, Boštjan; Yin, Chungen; Samec, Niko; Hriberšek, Matjaž; Kokalj, Filip; Zadravec, Matej

2018-07-15

Grate-fired boilers are commonly used to burn biomass/wastes for heat and power production. In spite of the recent breakthrough in integration of advanced secondary air systems in grate boilers, grate-firing technology needs to be advanced for higher efficiency and lower emissions. In this paper, innovative staging of combustion air and recycled flue gas in a 13 MW th waste wood-fired grate boiler is comprehensively studied based on a numerical model that has been previously validated. In particular, the effects of the jet momentum, position and orientation of the combustion air and recycled flue gas streams on in-furnace mixing, combustion and pollutant emissions from the boiler are examined. It is found that the optimized air and recycled flue gas jets remarkably enhance mixing and heat transfer, result in a more uniform temperature and velocity distribution, extend the residence time of the combustibles in the hot zone and improve burnout in the boiler. Optimizing the air and recycled flue gas jet configuration can reduce carbon monoxide emission from the boiler by up to 86%, from the current 41.0 ppm to 5.7 ppm. The findings of this study can serve as useful guidelines for novel design and optimization of the combustion air supply and flue gas recycling for grate boilers of this type. Copyright © 2018 Elsevier Ltd. All rights reserved.

Monitoring and performance analysis of AGR boilers during commissioning and power raising

International Nuclear Information System (INIS)

El-Nagdy, M.; Harrison, R.M.

1984-01-01

The installed boiler plant, for two 1300 MW AGR stations, is comprehensively instrumented for boiler control, performance assessment and component monitoring to ensure the integrity and safe operation of the plant during normal and faulty operating conditions. Plant instrumentation and computer systems installed at site for vibration analysis during the engineering runs and data acquisition during the power raising stage have been described. The results, from early rig investigations and the vibration testing during the unfueled engineering runs, indicate that the behaviour of the plant within the practical range of operating conditions is free from vibration problems. Also the analysis of the steady state thermal and hydrodynamic behaviour of the boiler plant during the power raising phase confirms the methods and computer models used for the boiler design. (author)

Application of 1-hydroxyethylidene-1, 1-diphosphonic acid in boiler water for industrial boilers.

Science.gov (United States)

Zeng, Bin; Li, Mao-Dong; Zhu, Zhi-Ping; Zhao, Jun-Ming; Zhang, Hui

2013-01-01

The primary method used for boiler water treatment is the addition of chemicals to industrial boilers to prevent corrosion and scaling. The static scale inhibition method was used to evaluate the scale inhibition performance of 1-hydroxyethylidene-1, 1-diphosphonic acid (HEDP). Autoclave static experiments were used to study the corrosion inhibition properties of the main material for industrial boilers (20# carbon steel) with an HEDP additive in the industrial boiler water medium. The electrochemical behavior of HEDP on carbon steel corrosion control was investigated using electrochemical impedance spectroscopy and Tafel polarization techniques. Experimental results indicate that HEDP can have a good scale inhibition effect when added at a quantity of 5 to 7 mg/L at a test temperature of not more than 100 °C. To achieve a high scale inhibition rate, the HEDP dosage must be increased when the test temperature exceeds 100 °C. Electrochemical and autoclave static experimental results suggest that HEDP has a good corrosion inhibition effect on 20# carbon steel at a concentration of 25 mg/L. HEDP is an excellent water treatment agent.

FIVE-YEAR RESULTS OF ADJUVANT RADIOTHER

Science.gov (United States)

Osa, Etin-Osa O.; DeWyngaert, Keith; Roses, Daniel; Speyer, James; Guth, Amber; Axelrod, Deborah; Kerimian, Maria Fenton; Goldberg, Judith D.; Formenti, Silvia C.

2015-01-01

Purpose/Objective A technique of prone breast radiotherapy delivered by a regimen of accelerated intensity modulated radiation therapy (IMRT) with a concurrent boost to the tumor bed, was developed at our institution. We report the five year results of this approach. Methods and Materials Between 2003–2006, 404 patients with Stage I–II breast cancer were prospectively enrolled into two consecutive protocols, institutional trials 03–30 and 05–181, that used the same regimen of 40.5Gy/15 fractions delivered to the index breast over 3 weeks, with a concomitant daily boost to the tumor bed of 0.5Gy (total dose=48Gy). All patients were treated after segmental mastectomy, had negative margins, and nodal assessment. Patients were set up prone: only if lung or heart volumes were in the field was a supine set-up attempted, and chosen if found to better spare these organs. Results 92% of patients were treated prone, 8% supine. 72% had stage I, 28% stage II invasive breast cancer. In-field lung volume ranged from 0 –228.27cc, mean: 19.65cc. In-field heart volume for left breast cancer patients ranged from 0–21.24cc, mean: 1.59cc. There was no heart in the field for right breast cancer patients. At a median follow-up of five years, the five-year cumulative incidence of isolated ipsilateral breast tumor recurrence was 0.82% (95% CI: 0.65–1.04). The five-year cumulative incidence of regional recurrence was 0.53% (95% CI:0.41–0.69) and the five-year overall cumulative death rate was 1.28% (95% CI: 0.48–3.38). 82% (95% CI: 77–85) of patients judged their final cosmetic result as excellent/good. Conclusions Prone accelerated IMRT with a concomitant boost results in excellent local control, optimal sparing of heart and lung, with good cosmesis. RTOG 10–05, a phase III, multi-institutional, randomized trial is ongoing and is evaluating the equivalence of a similar dose and fractionation approach to standard six weeks radiotherapy with a sequential boost. PMID

Basics about online boiler cleaning according to the Schwandorf principle; Grundlagen zur Online-Kesselreinigung nach dem Schwandorfer Prinzip

Energy Technology Data Exchange (ETDEWEB)

Krueger, Joerg [VWT Ing.-Buero, Schwandorf (Germany); Krueger, Sascha [IBK-Verfahrenstechnik, Bad Berka (Germany)

2013-10-01

In the Schwandorf waste-to-energy (WtE) plant more than ten years ago a wet online boiler cleaning system was developed which has the capability to clean the radiation passes of (WtE-, biomass- and refuse derived fuel (RDF)) boilers without damaging the boiler. During the development it was recognised that the method of atomising the washing agent (water) is highly influencing the effectiveness of cleaning by securing parts of the boiler (membrane walls). (orig.)

Enviro-exergy sustainability analysis of boiler evolution in district energy system

International Nuclear Information System (INIS)

Compton, M.; Rezaie, B.

2017-01-01

Investigations into energy resources are important from the point of energy sustainability. The principal objective of this study is to investigate the evolution of the operating boilers at the University of Idaho (UI) district energy plant through an exergy analysis. The biomass boiler uses western red cedar chips from nearby lumber mills and provides 95% of the steam requirements of the main campus of UI in Moscow, ID, USA. Thermodynamic analysis reveals a thermal efficiency of 76% and an exergy efficiency of 24% for the biomass boiler. A combustion model is developed to determine the primary emissions products of both the bone dry wood chips and natural gas fuels. CO 2 comprises 26% of the bone dry biomass emissions and 8% of the natural gas emissions products. Testing results of the biomass boiler exhaust stack show CO 2 emissions of 14% when an average moisture content of 33% is accounted for. An overview of the evolution of the energy plant is discussed, showing the generational differences in each boiler. By using a biomass fuel source, the cost per 1000 kg of steam produced is on average 63% lower than using natural gas, resulting in savings of over $1 million annually. - Highlights: • Exergy efficiency comparison of biomass and natural gas boilers. • Moisture content in biomass reduces average heating value and exergy efficiency. • Local sustainable energy sources can result in economic savings over fossil fuels. • Older boilers can have comparable efficiencies with newer ones after improvements.

Possibility analysis of combustion of torrefied biomass in 140 t/h PC boiler

Directory of Open Access Journals (Sweden)

Jagodzińska Katarzyna

2016-01-01

Full Text Available The study attempts to evaluate the impact of combustion of torrefied willow (Latin: Salix viminalis and palm kernel shell (Latin: Elaeis guineensis on the heat exchange in a 140 t/h PC boiler through an analysis of 6 cases for different boiler loads (60 %, 75 % and 100 % and a comparison with coal combustion. The analysis is premised on a 0-dimensional model based on the method presented in [15, 16, 17] and long-standing experimental measurements. Inter alia, the following results are presented: the temperature distribution of flue gases and the working medium (water/steam in characteristic points of the boiler as well as heat transfer coefficients for each element thereof. The temperature distribution of both fluids and the heat transfer coefficients are similar for all analysed fuels for each boiler load. However, the flue gas temperature at the outlet is higher in the case of torrefied biomass combustion. Due to that, there is an increase in the stack loss, which involves a decrease in the boiler efficiency. The conclusion is that torrefied biomass combustion is possible in a PC boiler without the need to change the boiler construction. However, it would be less effective than coal combustion.

Investigation of a Boiler's Furnace Aerodynamics with a Vortex Solid Fuel Combustion Scheme on Physical and Mathematical Models

Directory of Open Access Journals (Sweden)

Prokhorov V.B.,

2018-04-01

Full Text Available The important problem of developing the low-cost technologies that will be able to provide a deep decrease in the concentration of nitrogen oxides while maintaining fuel burn-up efficiency is considered. This paper presents the results of the aerodynamics study of the furnace of boiler TPP-210A on the base of the physical and mathematical models in the case when boiler retrofitting from liquid to solid slag removal with two to three times reduction of nitrogen oxide emissions and replacing the vortex burners with direct-flow burners. The need for these studies is due to the fact that the direct-flow burners are "collective action" burners, and efficient fuel combustion can be provided only by the interaction of fuel jets, secondary and tertiary air jets in the furnace volume. The new scheme of air staged combustion in a system of vertical vortexes of opposite rotation with direct-flow burners and nozzles and direct injection of Kuznetsky lean coal dust was developed. In order to test the functional ability and efficiency of the proposed combustion scheme, studies on the physical model of the boiler furnace and the mathematical model of the experimental furnace bench for the case of an isothermal fluid flow were carried out. Comparison showed an acceptable degree of coincidence of these results. In all studied regimes, pronounced vortices remain in both the vertical and horizontal planes, that indicates a high degree of mass exchange between jets and combustion products and the furnace aerodynamics stability to changes in regime factors.

Five-year workplace wellness intervention in the NHS.

Science.gov (United States)

Blake, Holly; Zhou, Dingyuan; Batt, Mark E

2013-09-01

Poor health and well-being has been observed among NHS staff and has become a key focus in current public health policy. The objective of this study was to deliver and evaluate a five-year employee wellness programme aimed at improving the health and well-being of employees in a large NHS workplace. A theory-driven multi-level ecological workplace wellness intervention was delivered including health campaigns, provision of facilities and health-promotion activities to encourage employees to make healthy lifestyle choices and sustained behaviour changes. An employee questionnaire survey was distributed at baseline (n = 1,452) and at five years (n = 1,134), including measures of physical activity, BMI, diet, self-efficacy, social support, perceived general health and mood, smoking behaviours, self-reported sickness absence, perceived work performance and job satisfaction. Samples were comparable at baseline and follow-up. At five years, significantly more respondents actively travelled (by walking or cycling both to work and for non-work trips) and more were active while at work. Significantly more respondents met current recommendations for physical activity at five years than at baseline. Fewer employers reported 'lack of time' as a barrier to being physically active following the intervention. Significantly lower sickness absence, greater job satisfaction and greater organisational commitment was reported at five years than at baseline. Improvements in health behaviours, reductions in sickness absence and improvements in job satisfaction and organisational commitment were observed following five years of a workplace wellness intervention for NHS employees. These findings suggest that health-promoting programmes should be embedded within NHS infrastructure.

Field Test of Boiler Primary Loop Temperature Controller

Energy Technology Data Exchange (ETDEWEB)

Glanville, P.; Rowley, P.; Schroeder, D.; Brand, L.

2014-09-01

Beyond these initial system efficiency upgrades are an emerging class of Advanced Load Monitoring (ALM) aftermarket controllers that dynamically respond to the boiler load, with claims of 10% to 30% of fuel savings over a heating season. For hydronic boilers specifically, these devices perform load monitoring, with continuous measurement of supply and in some cases return water temperatures. Energy savings from these ALM controllers are derived from dynamic management of the boiler differential, where a microprocessor with memory of past boiler cycles prevents the boiler from firing for a period of time, to limit cycling losses and inefficient operation during perceived low load conditions. These differ from OTR controllers, which vary boiler setpoint temperatures with ambient conditions while maintaining a fixed differential. PARR installed and monitored the performance of one type of ALM controller, the M2G from Greffen Systems, at multifamily sites in the city of Chicago and its suburb Cary, IL, both with existing OTR control. Results show that energy savings depend on the degree to which boilers are over-sized for their load, represented by cycling rates. Also savings vary over the heating season with cycling rates, with greater savings observed in shoulder months. Over the monitoring period, over-sized boilers at one site showed reductions in cycling and energy consumption in line with prior laboratory studies, while less over-sized boilers at another site showed muted savings.

40 CFR 68.168 - Five-year accident history.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Five-year accident history. 68.168 Section 68.168 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CHEMICAL ACCIDENT PREVENTION PROVISIONS Risk Management Plan § 68.168 Five-year accident history...

Researching the Performance of Dual-Chamber Fire-Tube Boiler Furnace

Directory of Open Access Journals (Sweden)

Khaustov Sergei

2015-01-01

Full Text Available Autonomous heating systems equipped with fire-tube or shell boilers show high effectiveness, consistent performance and great technical parameters. But there is a significant limitation of its thermal productivity due to the complexity of durable large diameter fire-tube bottoms implementation. Optimization of combustion aerodynamics can be the way to expand the fire-tube boilers performance limit. In this case lots of problems connected with reducing emissions of toxic substances, providing of burning stability, local heat stresses and aerodynamic resistances should be solved. To resolve the indicated problems, a modified model of dual-chamber fire-tube boiler furnace is proposed. The performance of suggested flame-tube was simulated using the proven computer-aided engineering software ANSYS Multiphysics. Results display proposed flame tube completely filled with moving medium without stagnant zones. Turbulent vortical combustion is observed even with the straight-through fuel supply. Active flue gas recirculation in suggested dual-chamber furnace reduces emissions of pollutants. Diminution of wall heat fluxes allows boiler operation at lower water treatment costs.

Analysis of fuel oil consumption in industrial steam boiler plants in Republic of Macedonia

International Nuclear Information System (INIS)

Armenski, Slave; Dimitrov, Konstantin; Tashevski, Done

1999-01-01

The steam boiler plants with heavy and light fuel oils in Republic of Macedonia are analyzed and determined. Depending of the working exit pressure, they are grouped in main industrial branches. The heat capacity and the steam production for the steam boiler plants are determined both total and separately by the different industrial branches. Depending of heat capacity and working period per year, the consumption of heavy and light oil is analyzed and determined particular for each industrial branch and total for all steam boiler plants for summer and winter period. (Author)

Elevated temperature failures in boiler tubes - case studies

International Nuclear Information System (INIS)

Gowrisankar, I.; Bandyopadhyay, G.

1989-01-01

Metallurgical investigation of boiler tube failures enables identification of failure mechanisms and the underlying cause related to boiler conditions. Some case studies in short term overheating, prolonged overheating and low cycle fatigue failures in boiler tubes are discussed. (author)

Thermal–hydraulic calculation and analysis of a 600 MW supercritical circulating fluidized bed boiler with annular furnace

International Nuclear Information System (INIS)

Wang, Long; Yang, Dong; Shen, Zhi; Mao, Kaiyuan; Long, Jun

2016-01-01

Highlights: • Non-linear model of supercritical CFB boiler with annular furnace is developed. • Many empirical correlations are used to solve the model. • The thermal–hydraulic characteristics of boiler are analyzed. • The results show that the design of the annular furnace is reasonable. - Abstract: The development of supercritical Circulating Fluidized Bed (CFB) boiler has great economic and environmental value. An entirely new annular furnace structure with outer and inner ring sidewalls for supercritical CFB boiler has been put forward by Institute of Engineering Thermophysics (IET), Chinese Academy of Sciences and Dongfang Boiler Group Co., Ltd. (DBC). Its outer and inner ring furnace structure makes more water walls arranged and reduces furnace height availably. In addition, compared with other additional evaporating heating surface structures such as mid-partition and water-cooled panels, the integrative structure can effectively avoid the bed-inventory overturn and improve the penetrability of secondary air. The conditions of the 600 MW supercritical CFB boiler including capability, pressure and mass flux are harsh. In order to insure the safety of boiler operation, it is very necessary to analyze the thermal–hydraulic characteristics of water-wall system. The water-wall system with complicated pipe arrangement is regarded as a network consisting of series-parallel circuits, pressure nodes and linking circuits, which represent vertical water-wall tubes, different headers and linking tubes, respectively. Based on the mass, momentum and energy conservation, a mathematical model is built, which consists of some simultaneous nonlinear equations. The mass flux in circuits, pressure drop between headers, outer vapor temperature of water-wall system and metal temperature data of tubes at the boiler maximum continuous rating (BMCR), 75% BMCR and 30% BMCR loads are obtained by solving the mathematical model. The results show that the vertical water

Installations of SNCR on bark-fired boilers

International Nuclear Information System (INIS)

Hjalmarsson, A.K.; Hedin, K.; Andersson, Lars

1997-01-01

Experience has been collected from the twelve bark-fired boilers in Sweden with selective non catalytic reduction (SNCR) installations to reduce emissions of nitrogen oxides. Most of the boilers have slope grates, but there are also two boilers with cyclone ovens and two fluidized bed boilers. In addition to oil there are also possibilities to burn other fuel types in most boilers, such as sludge from different parts of the pulp and paper mills, saw dust and wood chips. The SNCR installations seems in general to be of simple design. In most installations the injection nozzles are located in existing holes in the boiler walls. The availability is reported to be good from several of the SNCR installations. There has been tube leakage in several boilers. The urea system has resulted in corrosion and in clogging of one oil burner. This incident has resulted in a decision not to use SNCR system with the present design of the system. The fuel has also caused operational problems with the SNCR system in several of the installations due to variations in the moisture content and often high moisture content in bark and sludge, causing temperature variations. The availability is presented to be high for the SNCR system at several of the plants, in two of them about 90 %. The results in NO x reduction vary between the installations depending on boiler, fuel and operation. The emissions are between 45 and 100 mg NO 2 /MJ fuel input and the NO x reduction rates are in most installations between 30 and 40 %, the lowest 20 and the highest 70 %. 13 figs, 3 tabs

Increasing the thermal efficiency of boiler plant

Directory of Open Access Journals (Sweden)

Uyanchinov Evgeniy

2017-01-01

Full Text Available The thermal efficiency increase of boiler plant is actual task of scientific and technical researches. The optimization of boiler operating conditions is task complex, which determine by most probable average load of boiler, operating time and characteristics of the auxiliary equipment. The work purpose – the determination of thermodynamic efficiency increase ways for boiler plant with a gas-tube boiler. The tasks, solved at the research are the calculation of heat and fuel demand, the exergetic analysis of boilerhouse and heat network equipment, the determination of hydraulic losses and exergy losses due to restriction. The calculation was shown that the exergy destruction can be reduced by 2.39% due to excess air reducing to 10%; in addition the oxygen enrichment of air can be used that leads to reducing of the exergy destruction rate. The processes of carbon deposition from the side of flame and processes of scale formation on the water side leads to about 4.58% losses of fuel energy at gas-tube boiler. It was shown that the exergy losses may be reduced by 2.31% due to stack gases temperature reducing to 148 °C.

Improved Recovery Boiler Performance Through Control of Combustion, Sulfur, and Alkali Chemistry

Energy Technology Data Exchange (ETDEWEB)

Baxter, Larry L.

2008-06-09

This project involved the following objectives: 1. Determine black liquor drying and devolatilization elemental and total mass release rates and yields. 2. Develop a public domain physical/chemical kinetic model of black liquor drop combustion, including new information on drying and devolatilization. 3. Determine mechanisms and rates of sulfur scavenging in recover boilers. 4. Develop non-ideal, public-domain thermochemistry models for alkali salts appropriate for recovery boilers 5. Develop data and a one-dimensional model of a char bed in a recovery boiler. 6. Implement all of the above in comprehensive combustion code and validate effects on boiler performance. 7. Perform gasification modeling in support of INEL and commercial customers. The major accomplishments of this project corresponding to these objectives are as follows: 1. Original data for black liquor and biomass data demonstrate dependencies of particle reactions on particle size, liquor type, gas temperature, and gas composition. A comprehensive particle submodel and corresponding data developed during this project predicts particle drying (including both free and chemisorbed moisture), devolatilization, heterogeneous char oxidation, char-smelt reactions, and smelt oxidation. Data and model predictions agree, without adjustment of parameters, within their respective errors. The work performed under these tasks substantially exceeded the original objectives. 2. A separate model for sulfur scavenging and fume formation in a recovery boiler demonstrated strong dependence on both in-boiler mixing and chemistry. In particular, accurate fume particle size predictions, as determined from both laboratory and field measurements, depend on gas mixing effects in the boilers that lead to substantial particle agglomeration. Sulfur scavenging was quantitatively predicted while particle size required one empirical mixing factor to match data. 3. Condensed-phase thermochemistry algorithms were developed for salt

Water side corrosion prevention in boilers

International Nuclear Information System (INIS)

Zeid, A.

1993-01-01

Corrosion may be defined as a naturally occurring physical and chemical deterioration of a material due to reaction with the environment or surrounding atmosphere. In boilers the material is subjected on both sides to two different media which may cause severe corrosion. At the water side the content of O 2 considered one of the principal factors which determine the extent of corrosion in the boiler tubes. This paper deals with certain conditions that result in the increase of O 2 in the boiler water and hence increase the corrosion rate, to minimize the effect of these conditions a chemical treatment was carried out the results obtained indicated the success of the treatment procedure in corrosion prevention and boiler material protection. The treatment is traditional. But the study indicates how a simple mean could be applied to solve a serious problem. 4 tab

A statistical estimator for the boiler power and its related parameters

International Nuclear Information System (INIS)

Tang, H.

2001-01-01

To determine the boiler power accurately is important for both controlling the plant and maximizing the plant productivity. There are two computed boiler powers for each boiler. They are steam based boiler power and feedwater based boiler power. The steam based boiler power is computed as the enthalpy difference between the feedwater enthalpy and the boiler steam enthalpy. The feedwater based boiler power is computed as enthalpy absorbed by the feedwater. The steam based boiler power is computed in RRS program and used in calibrating the measured reactor power, while the feedwater based boiler power is computed in CSTAT program and used for indication. Since the steam based boiler power is used as feedback in the reactor control, it is chosen to be the one estimated in this work. Because the boiler power employs steam flow, feedwater flow and feedwater temperature measurements, and because any measurement contains constant or drifting noise and bias, the reconciliation and rectification procedures are needed to determine the boiler power more accurately. A statistic estimator is developed to perform the function of data reconciliation, gross error detection and instruments performance monitoring

Backstepping-based nonlinear adaptive control for coal-fired utility boiler-turbine units

International Nuclear Information System (INIS)

Fang, Fang; Wei, Le

2011-01-01

The control system of boiler-turbine unit plays an important role in improving efficiency and reducing emissions of power generation unit. The nonlinear, coupling and uncertainty of the unit caused by varying working conditions should be fully considered during the control system design. This paper presents an efficient control scheme based on backstepping theory for improving load adaptability of boiler-turbines in wide operation range. The design process of the scheme includes model preprocessing, control Lyapunov functions selection, interlaced computation of adaptive control laws, etc. For simplification and accuracy, differential of steam pipe inlet pressure and integral terms of target errors are adopted. Also, to enhance practicality, implementation steps of the scheme are proposed. A practical nonlinear model of a 500 MW coal-fired boiler-turbine unit is used to test the efficiency of the proposed scheme in different conditions.

46 CFR 61.05-15 - Boiler mountings and attachments.

Science.gov (United States)

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Boiler mountings and attachments. 61.05-15 Section 61.05... TESTS AND INSPECTIONS Tests and Inspections of Boilers § 61.05-15 Boiler mountings and attachments. (a....05-10. (b) Each stud or bolt for each boiler mounting that paragraph (c) of this section requires to...

Aspects of new material application for boilers construction

International Nuclear Information System (INIS)

Czerniawski, R.

1996-01-01

Review of steel types commonly used for energetic boilers construction has been done. The worldwide trends in new materials application for improvement of boilers quality have been discussed. The mechanical properties of boiler construction steels have been shown and compared. 3 refs, 5 figs, 1 tab

NOx Control Options and Integration for US Coal Fired Boilers

Energy Technology Data Exchange (ETDEWEB)

Mike Bockelie; Marc Cremer; Kevin Davis; Martin Denison; Adel Sarofim; Connie Senior; Hong-Shig Shim; Dave Swenson; Bob Hurt; Eric Suuberg; Eric Eddings; Kevin Whitty; Larry Baxter; Calvin Bartholomew; William Hecker

2006-06-30

This is the Final Report for DOE Cooperative Agreement No: DE-FC26-00NT40753. The goal of the project was to develop cost-effective analysis tools and techniques for demonstrating and evaluating low-NOx control strategies and their possible impact on boiler performance for boilers firing US coals. The Electric Power Research Institute (EPRI) provided co-funding for this program. This project included research on: (1) In furnace NOx control; (2) Impacts of combustion modifications on boiler operation; (3) Selective Catalytic Reduction (SCR) catalyst testing and (4) Ammonia adsorption/removal on fly ash. Important accomplishments were achieved in all aspects of the project. Rich Reagent Injection (RRI), an in-furnace NOx reduction strategy based on injecting urea or anhydrous ammonia into fuel rich regions in the lower furnace, was evaluated for cyclone-barrel and PC fired utility boilers. Field tests successfully demonstrated the ability of the RRI process to significantly reduce NOx emissions from a staged cyclone-fired furnace operating with overfire air. The field tests also verified the accuracy of the Computational Fluid Dynamic (CFD) modeling used to develop the RRI design and highlighted the importance of using CFD modeling to properly locate and configure the reagent injectors within the furnace. Low NOx firing conditions can adversely impact boiler operation due to increased waterwall wastage (corrosion) and increased soot production. A corrosion monitoring system that uses electrochemical noise (ECN) corrosion probes to monitor, on a real-time basis, high temperature corrosion events within the boiler was evaluated. Field tests were successfully conducted at two plants. The Ohio Coal Development Office provided financial assistance to perform the field tests. To investigate soot behavior, an advanced model to predict soot production and destruction was implemented into an existing reacting CFD modeling tool. Comparisons between experimental data collected

Suicide rates in five-year age-bands after the age of 60 years

DEFF Research Database (Denmark)

Shah, Ajit; Bhat, Ravi; Zarate-Escudero, Sofia

2016-01-01

-79 years) and the oldest old (80+ years) age groups. METHODS: Data on the number of suicides (International Classification of Diseases - ICD-10 codes, X60-84) in each of the eight five-year age-bands between the age-bands 60-64 years and 95-99 years in both gender for as many years as possible from 2000...... were ascertained from three sources: colleagues with access to national data, national statisics office websites and email contact with the national statistics offices. The population size for the corresponding years and age-bands was estimated for each country using data provided by the United Nations......BACKGROUND: There is paucity of studies examining suicide rates in narrow five-year age-bands after the age of 60 years. This study examined suicide rates in eight five-year age-bands between the age of 60 and 99 years because this will allow more precise comparison between the young old (60...

Final stage of first supercritical 460MW{sub e} CFB boiler construction. First experience

Energy Technology Data Exchange (ETDEWEB)

Goral, Damian [Foster Wheeler Energia Polska (Poland); Ostrowski, Waldemar [PKE (Poland)

2009-07-01

Circulating fluidized bed (CFB) boiler technology has been growing in size and number over the past two decades and it has established its position as utility scale boiler technology. Plant sizes up to 300 MW{sub e} are in operation today and designs for larger boilers are being developed. The next natural step for CFB technology is to go for supercritical steam parameters and larger boiler sizes. A Polish utility company Poludniowy Koncern Energetyczny SA (PKE) placed an order to Foster Wheeler Energia Oy for a 460 MW{sub e} supercritical CFB boiler for their Lagisza power plant. Contract was signed at the end of year 2002 and the engineering work is now ongoing. This will be the first supercritical once-through CFB boiler in the world. A modern power plant is designed for high efficiency not only for economical reasons but also for enhanced environmental performance in terms of reduced emissions and quantity of ash generated due to lower fuel consumption. Cutting CO{sub 2} emissions is one of the main drivers. To achieve these goals, supercritical steam parameters have been applied. Now this technology is available also for CFB technology. This combines a high plant efficiency with the other well known benefits of CFB technology, such as: fuel flexibility, low emissions and high availability. The boiler design for 460 MW{sub e} Lagisza power plant utilizes low mass flux BENSON Vertical once-through technology developed and licensed by Siemens AG, Germany. CFB boiler with low and uniform furnace heat flux is extremely well suited for the Benson technology providing a stable operation of the boiler also during load changes and abnormal operation conditions. The paper describes the 460 MW{sub e} supercritical CFB boiler concept and presents the technical solutions of the boiler design with auxiliary equipment, as well as first experiences from boiler erection period and commissioning. In spite of achieving this remarkable milestone the development of the CFB

Effect of Thermal Storage on the Performance of a Wood Pellet-fired Residential Boiler

Energy Technology Data Exchange (ETDEWEB)

Thomas, Butcher [Brookhaven National Laboratory (BNL), Upton, NY (United States). Sustainable Energy Technologies Dept.

2017-08-31

Interest in the direct use of biomass for thermal applications as a renewable technology is increasing as is also focus on air pollutant emissions from these sources and methods to minimize the impact. This work has focused on wood pellet-fired residential boilers, which are the cleanest fuel in this category. In the residential application the load varies strongly over the course of a year and a high fraction of the load is typically under 15% of the maximum boiler capacity. Thermal storage can be used even with boilers which have modulation capacity typically to 30% of the boiler maximum. One common pellet boiler was tested at full load and also at the minimum load used in the U.S. certification testing (15%). In these tests the load was steady over the test period. Testing was also done with an emulated load profile for a home in Albany, N.Y. on a typical January, March, and April day. In this case the load imposed on the boiler varied hourly under computer control, based on the modeled load for the example case used. The boiler used has a nominal output of 25 kW and a common mixed hardwood/softwood commercial pellet was used. Moisture content was 3.77%. A dilution tunnel approach was used for the measurement of particulate emissions, in accordance with U.S. certification testing requirements. The test results showed that the use of storage strongly reduces cycling rates under part load conditions. The transients which occur as these boilers cycle contribute to increased particulate emissions and reduced efficiency. The time period of a full cycle at a given load condition can be increased by increasing the storage tank volume and/or increasing the control differential range. It was shown that increasing the period strongly increased the measured efficiency and reduced the particulate emission (relative to the no storage case). The impact was most significant at the low load levels. Storage tank heat loss is shown to be a significant factor in thermal efficiency

Boiler-turbine life extension

Energy Technology Data Exchange (ETDEWEB)

Natzkov, S. [TOTEMA, Ltd., Sofia (Bulgaria); Nikolov, M. [CERB, Sofia (Bulgaria)

1995-12-01

The design life of the main power equipment-boilers and turbines is about 105 working hours. The possibilities for life extension are after normatively regulated control tests. The diagnostics and methodology for Boilers and Turbines Elements Remaining Life Assessment using up to date computer programs, destructive and nondestructive control of metal of key elements of units equipment, metal creep and low cycle fatigue calculations. As well as data for most common damages and some technical decisions for elements life extension are presented.

Does geographical variability influence five-year MACCE rates in the multicentre SYNTAX revascularisation trial?

Science.gov (United States)

Roy, Andrew K; Chevalier, Bernard; Lefèvre, Thierry; Louvard, Yves; Segurado, Ricardo; Sawaya, Fadi; Spaziano, Marco; Neylon, Antoinette; Serruys, Patrick A; Dawkins, Keith D; Kappetein, Arie Pieter; Mohr, Friedrich-Wilhelm; Colombo, Antonio; Feldman, Ted; Morice, Marie-Claude

2017-09-20

The use of multiple geographical sites for randomised cardiovascular trials may lead to important heterogeneity in treatment effects. This study aimed to determine whether treatment effects from different geographical recruitment regions impacted significantly on five-year MACCE rates in the SYNTAX trial. Five-year SYNTAX results (n=1,800) were analysed for geographical variability by site and country for the effect of treatment (CABG vs. PCI) on MACCE rates. Fixed, random, and linear mixed models were used to test clinical covariate effects, such as diabetes, lesion characteristics, and procedural factors. Comparing five-year MACCE rates, the pooled odds ratio (OR) between study sites was 0.58 (95% CI: 0.47-0.71), and countries 0.59 (95% CI: 0.45-0.73). By homogeneity testing, no individual site (X2=93.8, p=0.051) or country differences (X2=25.7, p=0.080) were observed. For random effects models, the intraclass correlation was minimal (ICC site=5.1%, ICC country=1.5%, p<0.001), indicating minimal geographical heterogeneity, with a hazard ratio of 0.70 (95% CI: 0.59-0.83). Baseline risk (smoking, diabetes, PAD) did not influence regional five-year MACCE outcomes (ICC 1.3%-5.2%), nor did revascularisation of the left main vs. three-vessel disease (p=0.241), across site or country subgroups. For CABG patients, the number of arterial (p=0.49) or venous (p=0.38) conduits used also made no difference. Geographic variability has no significant treatment effect on MACCE rates at five years. These findings highlight the generalisability of the five-year outcomes of the SYNTAX study.

BOILER MATERIALS FOR ULTRASUPERCRITICAL COAL POWER PLANTS

Energy Technology Data Exchange (ETDEWEB)

R. Viswanathan; K. Coleman

2003-01-20

The principal objective of this project is to develop materials technology for use in ultrasupercritical (USC) plant boilers capable of operating with 760 C (1400 F), 35 MPa (5000 psi) steam. In the 21st century, the world faces the critical challenge of providing abundant, cheap electricity to meet the needs of a growing global population while at the same time preserving environmental values. Most studies of this issue conclude that a robust portfolio of generation technologies and fuels should be developed to assure that the United States will have adequate electricity supplies in a variety of possible future scenarios. The use of coal for electricity generation poses a unique set of challenges. On the one hand, coal is plentiful and available at low cost in much of the world, notably in the U.S., China, and India. Countries with large coal reserves will want to develop them to foster economic growth and energy security. On the other hand, traditional methods of coal combustion emit pollutants and CO{sub 2} at high levels relative to other generation options. Maintaining coal as a generation option in the 21st century will require methods for addressing these environmental issues. This project has established a government/industry consortium to undertake a five-year effort to evaluate and develop of advanced materials that allow the use of advanced steam cycles in coal-based power plants. These advanced cycles, with steam temperatures up to 760 C, will increase the efficiency of coal-fired boilers from an average of 35% efficiency (current domestic fleet) to 47% (HHV). This efficiency increase will enable coal-fired power plants to generate electricity at competitive rates (irrespective of fuel costs) while reducing CO{sub 2} and other fuel-related emissions by as much as 29%. Success in achieving these objectives will support a number of broader goals. First, from a national prospective, the program will identify advanced materials that will make it possible to

Numerical Modeling of the Effect of Thawing of Soil in the Area of Placing Tanks for Storage Fuel of Thermal Power Plants and Boiler

Directory of Open Access Journals (Sweden)

Polovnikov V.Yu.

2016-01-01

Full Text Available This paper describes the numerical modeling of heat transfer in the area placing of the tank for storage fuel of thermal power plant and boiler with considering the influence of thawing of the soil. We have established that the thawing of the soil in the area of placing of the tank for storage fuel of thermal power plant and boiler have little effect on the change of heat loss.

46 CFR 176.812 - Pressure vessels and boilers.

Science.gov (United States)

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Pressure vessels and boilers. 176.812 Section 176.812... TONS) INSPECTION AND CERTIFICATION Material Inspections § 176.812 Pressure vessels and boilers. (a.... (b) Periodic inspection and testing requirements for boilers are contained in § 61.05 in subchapter F...

49 CFR 230.36 - Hydrostatic testing of boilers.

Science.gov (United States)

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Hydrostatic testing of boilers. 230.36 Section 230... Appurtenances Pressure Testing of Boilers § 230.36 Hydrostatic testing of boilers. (a) Time of test. The... to any hydrostatic pressure. Hydrostatic testing required by these rules shall be conducted at 25...

Hybrid system for fouling control in biomass boilers

Energy Technology Data Exchange (ETDEWEB)

Romeo, Luis M.; Gareta, Raquel [Centro de Investigacin de Recursos y Consumos Energeticos (CIRCE), Universidad de Zaragoza, Centro Politecnico Superior, Mareda de Luna, 3, Zaragoza 50018, (Spain)

2006-12-15

Renewable energy sources are essential paths towards sustainable development and CO{sub 2} emission reduction. For example, the European Union has set the target of achieving 22% of electricity generation from renewable sources by 2010. However, the extensive use of this energy source is being avoided by some technical problems as fouling and slagging in the surfaces of boiler heat exchangers. Although these phenomena were extensively studied in the last decades in order to optimize the behaviour of large coal power boilers, a simple, general and effective method for fouling control has not been developed. For biomass boilers, the feedstock variability and the presence of new components in ash chemistry increase the fouling influence in boiler performance. In particular, heat transfer is widely affected and the boiler capacity becomes dramatically reduced. Unfortunately, the classical approach of regular sootblowing cycles becomes clearly insufficient for them. Artificial Intelligence (AI) provides new means to undertake this problem. This paper illustrates a methodology based on Neural Networks (NNs) and Fuzzy-Logic Expert Systems to select the moment for activating sootblowing in an industrial biomass boiler. The main aim is to minimize the boiler energy and efficiency losses with a proper sootblowing activation. Although the NN type used in this work is well-known and the Hybrid Systems had been extensively used in the last decade, the excellent results obtained in the use of AI in industrial biomass boilers control with regard to previous approaches makes this work a novelty. (Author)

Soot blowing methods and soot steam consumption in Swedish recovery boilers; Sotningsmetoder och sotaangfoerbrukning i svenska sodapannor

Energy Technology Data Exchange (ETDEWEB)

Svedin, Kristoffer; Wallin, Erik; Ahlroth, Mikael

2008-09-15

The aim with the report was to put together a description of the current state of the sootblowing systems at Swedish recovery boilers, and to explain differences in cleanability and sootblowing efficiency. In chapter 4 a summary of new techniques and alternative soot blowing methods is found. The report is intended for persons working in the pulp industry. To facilitate the benchmarking the recovery boilers have been divided into two groups. Group A comprises recovery boilers which only have one stop per year and the remaining recovery boilers with more than one stop are classified into group B. The following conclusions, based on the recovery boiler design specifications, are of importance to achieve high boiler availability: Low furnace load; High recovery boiler, wide furnace bottom area; Modern air ports; Small or no correlation between cross pitch division in heat surfaces and cleanability could be seen. The expectation was to identify such a relation. However there are doubts on the correctness in reported data. The amount of chlorine and potassium is assumed to affect the cleanability for a few recovery boilers, but for the majority the amounts are low and most likely do not impact the operation. Because of the large impact of the recovery boilers design data (furnace area, load etc.) on the sootblowing, it has been hard to identify the relation cleanability contra sootblowing system. The relations that could be seen are: No distinction between normally designed nozzles and 'high efficiency' nozzles could be identified. The operational conditions for the different models differ a lot and the effect of nozzle type could not be distinguished. Only a minority of the soot blowing sequences are known from the study. In the recovery boilers with problematic areas improvements can be made in the soot blowing sequence. Four recovery boilers are using intelligent soot blowing of some kind. Two of these boilers have low availability and the other two have

Simulation and testing of a new condensing boiler

International Nuclear Information System (INIS)

Rosa, L.; Tosato, R.

1987-01-01

The paper describes a new condensing boiler, characterized by the evacuation of flue-gases by natural draft. The best result is the consequent simplification of manufacturing, hook-up and operation of the boiler. Seasonal efficiency of the boiler, which operates with flue-gases conditioning to assure natural draft, rests about at same levels as for conventional condensing boilers. The authors emphasize the difficulty of simulate natural draft mechanism by mathematics because, in this case, flow of flue-gases and air at the draft diverter is strongly three-dimensional

Co-firing of Coal with Biomass and Waste in Full-scale Suspension-fired Boilers

DEFF Research Database (Denmark)

Dam-Johansen, Kim; Jappe Frandsen, Flemming; Jensen, Peter Arendt

2013-01-01

and boiler manufacturers to optimize design and operation and minimize cost and environmental impact using alternative fuels in suspension fired boilers. Our contribution has been made via a combination of full-scale measuring campaigns, pilot-scale studies, lab-scale measurements and modeling tools....... The research conducted has addressed many issues important for co-firing, i.e. fuel processing, ash induced boiler deposit formation and corrosion, boiler chamber fuel conversion and emission formation, influence on flue gas cleaning equipment and the utilization of residual products. This paper provides...... research has provided results with implications for operation of milling and burner equipment, appropriate fuel mixing strategies, minimization of ash deposit formation and corrosion, minimization of NO formation, appropriate operation of SCR catalyst equipment and utilization of residual products...

Influence of boiler load on water tubes burnout

Energy Technology Data Exchange (ETDEWEB)

Said, S.A.M.; Habib, M.A.; Badr, H.M.; Mansour, R. [King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia). Dept. of Mechanical Engineering

2009-07-01

The influence of boiler loads on water tube burnout was investigated. The in-service boiler had 2 burners at different levels located in the front of the burner's wall. Homogenous-flow and separated-flow models were designed to simulate the water circulation and combustion processes inside the boiler tubes. Heat flux calculations were derived by solving the conservation of mass, momentum, and energy equations and species concentration as well as by solving turbulence, reaction rate, and radiation model equations. Results of the study showed that heat flux during full loads ranged from close to 0 to 270 kW/m2. The right side screen wall of the burner exhibited higher heat flux values in the middle region of the wall where large areas were subjected to heat flux close to a maximum of 270 kW/m2. Results also included reductions in heat flux values at partial loads. Maximum values were reduced from 270 kW/m2 ato 230 kW/m2 at 75 per cent capacity and 200 kW/m2 at 60 per cent capacity. The rate of steam generation increased from 0.1 kg/s to 0.153 kg/s when the distance from the burner wall increased from 2 meters to 12 meters. 10 refs., 10 figs.

Columbine High: Five Years Later

Science.gov (United States)

Hurst, Marianne D.

2004-01-01

A few weeks before the fifth anniversary of the Columbine High School shootings on April 20, 1999, Principal Frank DeAngelis reflects on how his school has changed over the past five years. Much like the September 11, 2001 terrorist attacks against the United States, "Columbine" carries a chilling meaning that resonates across the…

The Technology Introduction of Chain Boiler Energy Conservation Transformation

Science.gov (United States)

Li, Henan; Liu, Xiwen; Yuan, Hong; Lin, Jiadai; Zhang, Yu

2017-12-01

Introduced the present status of chain boiler efficiency is low, the system analysis of the chain boiler optimization and upgrading of technology, for the whole progress of chain boiler to provide some ideas and reference.

46 CFR 115.812 - Pressure vessels and boilers.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Pressure vessels and boilers. 115.812 Section 115.812... CERTIFICATION Material Inspections § 115.812 Pressure vessels and boilers. (a) Pressure vessels must be tested... testing requirements for boilers are contained in § 61.05 in subchapter F of this chapter. [CGD 85-080, 61...

46 CFR 56.50-30 - Boiler feed piping.

Science.gov (United States)

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Boiler feed piping. 56.50-30 Section 56.50-30 Shipping... APPURTENANCES Design Requirements Pertaining to Specific Systems § 56.50-30 Boiler feed piping. (a) General... least two separate means of supplying feed water for the boilers. All feed pumps shall be fitted with...

Stationary Engineers Apprenticeship. Related Training Modules. 12.1-12.9. Boilers.

Science.gov (United States)

Lane Community Coll., Eugene, OR.

This learning module, one in a series of 20 related training modules for apprentice stationary engineers, deals with boilers. Addressed in the individual instructional packages included in the module are the following topics: firetube and watertube boilers; boiler construction; procedures for operating and cleaning boilers; and boiler fittings,…

A NOx control regulation for electric utility boilers in California

International Nuclear Information System (INIS)

Price, D.R.

1992-01-01

The reduction of oxides of nitrogen emissions is becoming an increasingly important part of ozone attainment plans. As a part of its ozone attainment plan, the Ventura County (California) Air Pollution Control Board adopted in June, 1991, a regulation (Rule 59) to limit oxides of nitrogen emissions from four electrical utility boilers in the county. Rule development took two years and involved considerable public input. The emission limit for each of two 750 megawatt units is set at 0.10 pounds of NO x per megawatt-hour net after June, 1994. The emission limit for each of two 215 megawatt units is 0.20 pounds of NO x per megawatt-hour after June, 1996. Additional limitations are included for fuel oil operation. The rule does not specify an emission control technology. Conventional selective catalytic reduction, urea injection and combustion modifications are considered the technologies most likely to be used to comply. At $17,613 per ton of NO x reduced for the two large boilers and $8.992 per ton of NO x reduced for the small boilers, the rule is considered cost effective. The capital cost for conventional selective catalytic reduction systems on all four boilers is expected to be in excess of $210,000,000

Development of combined low-emissions burner devices for low-power boilers

Science.gov (United States)

Roslyakov, P. V.; Proskurin, Yu. V.; Khokhlov, D. A.

2017-08-01

Low-power water boilers are widely used for autonomous heat supply in various industries. Firetube and water-tube boilers of domestic and foreign manufacturers are widely represented on the Russian market. However, even Russian boilers are supplied with licensed foreign burner devices, which reduce their competitiveness and complicate operating conditions. A task of developing efficient domestic low-emissions burner devices for low-power boilers is quite acute. A characteristic property of ignition and fuel combustion in such boilers is their flowing in constrained conditions due to small dimensions of combustion chambers and flame tubes. These processes differ significantly from those in open combustion chambers of high-duty power boilers, and they have not been sufficiently studied yet. The goals of this paper are studying the processes of ignition and combustion of gaseous and liquid fuels, heat and mass transfer and NO x emissions in constrained conditions, and the development of a modern combined low-emissions 2.2 MW burner device that provides efficient fuel combustion. A burner device computer model is developed and numerical studies of its operation on different types of fuel in a working load range from 40 to 100% of the nominal are carried out. The main features of ignition and combustion of gaseous and liquid fuels in constrained conditions of the flame tube at nominal and decreased loads are determined, which differ fundamentally from the similar processes in steam boiler furnaces. The influence of the burner devices design and operating conditions on the fuel underburning and NO x formation is determined. Based on the results of the design studies, a design of the new combined low-emissions burner device is proposed, which has several advantages over the prototype.

Key Royale bridge five year evaluation.

Science.gov (United States)

2013-06-01

This report describes the design, construction, instrumentation, and five-year evaluation of the Key Royale Bridge substructure. The primary focus was the evaluation of the implementation of highly reactive supplementary cementitious materials (SCM) ...

New materials for boilers in USC power plants

International Nuclear Information System (INIS)

Hong, Sung Ho; Hong, Seok Joo

2003-01-01

The efficiency of boiler in fossil power plants is a strong function of steam temperature and pressure. Thus, the main technology of increasing boiler efficiency is the development of stronger high temperature materials, capable of operating under high stresses at ever increasing temperature. This paper will presents the new material relating to boiler of USC power plant

Launching PPARC's five year strategy programme

CERN Document Server

2003-01-01

"Over one hundred delegates from Parliament, Whitehall and Industry attended a reception on Tuesday night (25 November) to mark the launch the Particle Physics and Astronomy Research Council's (PPARC) Five Year Plan" (1 page).

Assessment of the candidate markets for liquid boiler fuels

Energy Technology Data Exchange (ETDEWEB)

None

1979-12-01

Liquid fuels can be produced from coal in a number of indirect and direct liquefaction processes. While indirect coal liquefaction has been proved commercially outside the United States, most attention in this country has focused on the direct liquefaction processes, which include the processes under examination in this report; namely, the Exxon Donor Solvent (EDS), the H-Coal, and the Solvent Refined Coal (SRC) II processes. The objectives of the study were to: compare the boiler fuels of direct coal liquefaction with residual fuel oil (No. 6 fuel oil) including physical characteristics and environmental hazards, such as carcinogenic characteristics and toxic hazard characteristics; determine whether a boiler fuel market would exist for the coal liquefaction products given their physical characteristics and potential environmental hazards; determine the advantages of utilizing methanol as a boiler fuel on a continuous basis in commercial boilers utilizing existing technology; identify the potential regional candidate markets for direct coal liquefaction products as liquid boiler fuels; determine the distributing and handling costs associated with marketing coal liquefaction products as liquid boiler fuels; determine the current regulatory issues associated with the marketing of coal liquefaction products as boiler fuels; and determine and evaluate other institutional issues associated with the marketing of direct coal liquefaction products as boiler fuels.

46 CFR 109.555 - Propulsion boilers.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Propulsion boilers. 109.555 Section 109.555 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.555 Propulsion boilers. The master or person in charge and the engineer in charge shall...

Research of power fuel low-temperature vortex combustion in industrial boiler based on numerical modelling

Directory of Open Access Journals (Sweden)

Orlova K.Y.

2017-01-01

Full Text Available The goal of the presented research is to perform numerical modelling of fuel low-temperature vortex combustion in once-through industrial steam boiler. Full size and scaled-down furnace model created with FIRE 3D software and was used for the research. All geometrical features were observed. The baseline information for the low-temperature vortex furnace process are velocity and temperature of low, upper and burner blast, air-fuel ratio, fuel consumption, coal dust size range. The obtained results are: temperature and velocity three dimensional fields, furnace gases and solid fuel ash particles concentration.

Evaluation of iron aluminide weld overlays for erosion - corrosion resistant boiler tube coatings in low NO{sub x} boilers

Energy Technology Data Exchange (ETDEWEB)

DuPont, J.N.; Banovic, S.W.; Marder, A.R. [Lehigh Univ., Bethlehem, PA (United States)

1996-08-01

Low NOx burners are being installed in many fossil fired power plants in order to comply with new Clean Air Regulations. Due to the operating characteristics of these burners, boiler tube sulfidation corrosion is often enhanced and premature tube failures can occur. Failures due to oxidation and solid particle erosion are also a concern. A program was initiated in early 1996 to evaluate the use of iron aluminide weld overlays for erosion/corrosion protection of boiler tubes in Low NOx boilers. Composite iron/aluminum wires will be used with the Gas Metal Arc Welding (GMAW) process to prepare overlays on boiler tubes steels with aluminum contents from 8 to 16wt%. The weldability of the composite wires will be evaluated as a function of chemical composition and welding parameters. The effect of overlay composition on corrosion (oxidation and sulfidation) and solid particle erosion will also be evaluated. The laboratory studies will be complemented by field exposures of both iron aluminide weld overlays and co-extruded tubing under actual boiler conditions.

10 CFR 431.82 - Definitions concerning commercial packaged boilers.

Science.gov (United States)

2010-01-01

... gases. Manufacturer of a commercial packaged boiler means any person who manufactures, produces... 10 Energy 3 2010-01-01 2010-01-01 false Definitions concerning commercial packaged boilers. 431.82... COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Packaged Boilers § 431.82 Definitions concerning commercial...

29 CFR 1915.162 - Ship's boilers.

Science.gov (United States)

2010-07-01

... 29 Labor 7 2010-07-01 2010-07-01 false Ship's boilers. 1915.162 Section 1915.162 Labor Regulations Relating to Labor (Continued) OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR (CONTINUED) OCCUPATIONAL SAFETY AND HEALTH STANDARDS FOR SHIPYARD EMPLOYMENT Ship's Machinery and Piping Systems § 1915.162 Ship's boilers. (a) Before...

Modeling and sliding mode predictive control of the ultra-supercritical boiler-turbine system with uncertainties and input constraints.

Science.gov (United States)

Tian, Zhen; Yuan, Jingqi; Zhang, Xiang; Kong, Lei; Wang, Jingcheng

2018-05-01

The coordinated control system (CCS) serves as an important role in load regulation, efficiency optimization and pollutant reduction for coal-fired power plants. The CCS faces with tough challenges, such as the wide-range load variation, various uncertainties and constraints. This paper aims to improve the load tacking ability and robustness for boiler-turbine units under wide-range operation. To capture the key dynamics of the ultra-supercritical boiler-turbine system, a nonlinear control-oriented model is developed based on mechanism analysis and model reduction techniques, which is validated with the history operation data of a real 1000 MW unit. To simultaneously address the issues of uncertainties and input constraints, a discrete-time sliding mode predictive controller (SMPC) is designed with the dual-mode control law. Moreover, the input-to-state stability and robustness of the closed-loop system are proved. Simulation results are presented to illustrate the effectiveness of the proposed control scheme, which achieves good tracking performance, disturbance rejection ability and compatibility to input constraints. Copyright © 2018 ISA. Published by Elsevier Ltd. All rights reserved.

Utility boiler computer modeling experience in the USA for practical furnace air port and low NOx burner field design

Energy Technology Data Exchange (ETDEWEB)

Breen, B.P.; Urich, J.A.; Krippene, B.C. [ESA, Inc. (United States)

2000-07-01

This paper presents several examples of where effective furnace and low NOx burner modeling has produced substantial advantages to the low NOx combustion system designer. Using practical boiler furnace air injection port and low NOx burner maths modeling as an integral part of the design process has often made the difference between a successful low NOx combustion system field conversion project and an unsuccessful one.

Fiscal Year 1996 Annual Report and Five-Year (1996-2000) Strategic Investment Plan

Science.gov (United States)

1996-03-01

Laboratory vn SERDP ACRONYMS LAAP LAMS LANL LARPS LCA LCAAP LIBS LIF LIN LIS LLNL LMS LNAPL LOVA LRS&T MADOM MAHRSI MARPOL MAS...FY 1995 $(K) Boiler/Engine Emissions Evaluation of Metal Perovskite Catalysts for Nox Reduction (AF) 25 Compact, Closed-Loop Controlled Waste...3 z re \\ > <: pq O- CP-2 SERDP COMPLIANCE SERDP FY96 PROJECT 1. SERDP Thrust Area: Compliance 2. Title: Evaluation of Metal Perovskite

Steam generators and waste heat boilers for process and plant engineers

CERN Document Server

Ganapathy, V

2014-01-01

Incorporates Worked-Out Real-World ProblemsSteam Generators and Waste Heat Boilers: For Process and Plant Engineers focuses on the thermal design and performance aspects of steam generators, HRSGs and fire tube, water tube waste heat boilers including air heaters, and condensing economizers. Over 120 real-life problems are fully worked out which will help plant engineers in evaluating new boilers or making modifications to existing boiler components without assistance from boiler suppliers. The book examines recent trends and developments in boiler design and technology and presents novel idea

40 CFR 63.988 - Incinerators, boilers, and process heaters.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Incinerators, boilers, and process... Routing to a Fuel Gas System or a Process § 63.988 Incinerators, boilers, and process heaters. (a) Equipment and operating requirements. (1) Owners or operators using incinerators, boilers, or process...

Numerical investigation towards a HiTAC condition in a 9MW heavy fuel-oil boiler

NARCIS (Netherlands)

Zhu, Shanglong; Venneker, Bart; Roekaerts, Dirk; Pozarlik, Artur; van der Meer, Theo

2013-01-01

In this study, several conditions in a 9 MW heavy fuel-oil boiler were numerically studied in order to get a better understanding of the application of HiTAC in such a boiler. Simulations were done with an Euler- Lagrange approach. The Eddy Dissipation model was used for combustion. Simulation

Annex A1: cornerstone of the five-yearly review

CERN Multimedia

Staff Association

2016-01-01

As a reminder; the purpose of the five-yearly review is to review the financial and social conditions of all CERN personnel whether employed (MPE) or associated (MPA)! In December 2015, the CERN Council approved the package proposed by the Management. Early this year, and as final act of the 2015 five-yearly review, the CERN Council may decide, if necessary and appropriate, to review the procedures defined in Annex A1 and applicable to future five-yearly reviews. At the meeting of TREF (TRipartite Employment Forum)  in early March 2016 discussions will take place between all stakeholders (representatives of Member States, Management and the Staff Association) and Council will take a decision in June 2016, on the basis of the Management's recommendations. What does Annex A1 say and where can I find it? Annex A1 (Article S V 1.02) is a part of the Staff Rules and Regulations. This annex defines: The five-yearly review of the financial and social conditions of the staff, fellows and MPA; The a...

Evaluation of conditions of SNCR in small boilers

International Nuclear Information System (INIS)

Kullendorff, A.; Lorentzon, K.

1996-04-01

The report describes the first part of a project 'SNCR for small boilers', supported by Vaermeforsk (Thermal Engineering Research Institute), with the purpose of assessing the potential for SNCR in small boilers. Given favourable conditions, the project was to be continued in a second part with the demonstration of a SNCR system in a small boiler (or several boilers). During the base establishment, the temperatures in four locations per boiler, in a couple of horizontal or vertical levels and at 2-3 thermal outputs, were measured. Out of the four locations two showed temperatures mainly within the theoretical temperature window for SNCR. These locations were used during the try-out tests to inject urea and ammonia. The locations and the equipment used during the try-out tests together with existing operation strategies seem to limit the reduction levels to approximately 10-20% at acceptable levels of ammonia slip. The measurements and try-out tests carried out does not provide enough basis for forming any general conclusions concerning SNCR in small boilers. Neither the base establishment nor the try-out tests included any optimisation of the boilers regarding the operation strategy or, for the try-out tests, locations and equipment (drop size, flow shape and direction). Therefore, it is likely to believe that better results can be obtained, given other conditions of operation and using well established SNCR technology, adapted to the circumstances. 2 refs, 27 figs, 5 tabs

Application of ELD and load forecast in optimal operation of industrial boiler plants equipped with thermal stores

International Nuclear Information System (INIS)

Cao Jiacong

2007-01-01

Optimal operation of industrial boiler plants with objects of high energy efficiency and low fuel cost is still well worth investigating when energy problem becomes a world's concern, for there are a great number of boiler plants serving industries. The optimization of operation is a measure that is less expensive and easier to carry out than many other measures. Economic load dispatch (ELD) is an effective approach to optimal operation of industrial boiler plants. In the paper a newly developed method referred to as the method of minimum-departure model (MDM) is used in the ELD for boiler plants. It is more convenient for carrying out ELD when boiler plants are equipped with thermal energy stores that usually adopt the working mode of optimal segmentation of a daily load curve. In the case of industrial boiler plants, ELD needs a prerequisite, viz., the accurate load forecast, which is performed using artificial neural networks in this paper. A computer program for the optimal operation was completed and applied to an example, which results the minimum daily fuel cost of the whole boiler plant

assessment of some performance characteristics of refuse boiler ...

African Journals Online (AJOL)

TIMZY

2013-07-02

Jul 2, 2013 ... A pioneer palm oil boiler unit, in an immense power self-contained oil mill, impaired by many years of accumulated ... revealed that under a single shift operating mode (8 hours), a time saving of 72 minutes arising from the effectiveness of ... electric power generation and for other processing equipment and ...

Effect of Pellet Boiler Exhaust on Secondary Organic Aerosol Formation from α-Pinene.

Science.gov (United States)

Kari, Eetu; Hao, Liqing; Yli-Pirilä, Pasi; Leskinen, Ari; Kortelainen, Miika; Grigonyte, Julija; Worsnop, Douglas R; Jokiniemi, Jorma; Sippula, Olli; Faiola, Celia L; Virtanen, Annele

2017-02-07

Interactions between anthropogenic and biogenic emissions, and implications for aerosol production, have raised particular scientific interest. Despite active research in this area, real anthropogenic emission sources have not been exploited for anthropogenic-biogenic interaction studies until now. This work examines these interactions using α-pinene and pellet boiler emissions as a model test system. The impact of pellet boiler emissions on secondary organic aerosol (SOA) formation from α-pinene photo-oxidation was studied under atmospherically relevant conditions in an environmental chamber. The aim of this study was to identify which of the major pellet exhaust components (including high nitrogen oxide (NO x ), primary particles, or a combination of the two) affected SOA formation from α-pinene. Results demonstrated that high NO x concentrations emitted by the pellet boiler reduced SOA yields from α-pinene, whereas the chemical properties of the primary particles emitted by the pellet boiler had no effect on observed SOA yields. The maximum SOA yield of α-pinene in the presence of pellet boiler exhaust (under high-NO x conditions) was 18.7% and in the absence of pellet boiler exhaust (under low-NO x conditions) was 34.1%. The reduced SOA yield under high-NO x conditions was caused by changes in gas-phase chemistry that led to the formation of organonitrate compounds.

Suicide rates in five-year age-bands after the age of 60 years: the international landscape.

Science.gov (United States)

Shah, Ajit; Bhat, Ravi; Zarate-Escudero, Sofia; DeLeo, Diego; Erlangsen, Annette

2016-01-01

There is paucity of studies examining suicide rates in narrow five-year age-bands after the age of 60 years. This study examined suicide rates in eight five-year age-bands between the age of 60 and 99 years because this will allow more precise comparison between the young old (60-79 years) and the oldest old (80+ years) age groups. Data on the number of suicides (International Classification of Diseases - ICD-10 codes, X60-84) in each of the eight five-year age-bands between the age-bands 60-64 years and 95-99 years in both gender for as many years as possible from 2000 were ascertained from three sources: colleagues with access to national data, national statisics office websites and email contact with the national statistics offices. The population size for the corresponding years and age-bands was estimated for each country using data provided by the United Nations website. In men, suicide rates continued to increase for each of the seven five-year age-bands from 60-64 years to 90-94 years age-band, and then declined slightly for the 95-99 year age-band. In women, suicide rates continued to increase for each of the six five-year age-bands from 60-64 years to 85-89 years age-bands, and then declined slightly for the 90-94 years and 95-99 years age-bands. The overall global suicide rates for each of the eight five-year age-bands are sufficiently large for them to constitute a public health concern. This is especially important given the ongoing rise in the elderly population size and the paucity of data on risk and protective factors for suicide in the five-year age-bands after the age of 60 years.

a Study of Using Hydrogen Gas for Steam Boiler in CHOLOR- Alkali Manufacturing

Science.gov (United States)

Peantong, Sasitorn; Tangjitsitcharoen, Somkiat

2017-06-01

Main products of manufacturing of Cholor - Alkali, which commonly known as industrial chemical, are chlorine gas (Cl2), Sodium Hydroxide (NaOH) and hydrogen gas (H2). Chorine gas and sodium hydroxide are two main products for commercial profit; where hydrogen gas is by product. Most industries release hydrogen gas to atmosphere as it is non-profitable and less commercial scale. This study aims to make the most use of hydrogen as a substitute energy of natural gas for steam boiler to save energy cost. The second target of this study is to reduce level of CO2 release to air as a consequence of boiler combustion. This study suggests to install boiler that bases on hydrogen as main power with a high turndown ratio of at least 1:6. However, this case study uses boiler with two mode such as natural gas (NG) mode and mixed mode as they need to be flexible for production. Never the less, the best boiler selection is to use single mode energy of hydrogen. The most concerned issue about hydrogen gas is explosion during combustion stage. Stabilization measures at emergency stop is introduced to control H2 pressure to protect the explosion. This study varies ratio of natural gas to hydrogen gas to find the optimal level of two energy sources for boiler and measure total consumption through costing model; where CO2 level is measured at the boiler stack. The result of this study shows that hydrogen gas can be a substitute energy with natural gas and can reduce cost. Natural gas cost saving is 248,846 baht per month and reduce level of NOx is 80 ppm 7% O2 and 2 % of CO2 release to air as a consequence of boiler combustion.

Comparative analysis of heat pump and biomass boiler for small detached house heating

Directory of Open Access Journals (Sweden)

Olkowski Tomasz

2017-01-01

Full Text Available The purpose of the work is to answer the question - which of the two selected heat sources is more economically beneficial for small detached house: heat pump or biomass boiler fuelled with wood-pellets? The comparative analysis of these sources was carried out to discuss the issue. First, cost of both, equipment and operation of selected heat systems were analysed. Additionally, CO2 emission levels associated with these heat systems were determined. The comparative analysis of the costs of both considered heat systems showed that equipment cost of heat pump system is considerably bigger than the cost of biomass boiler system. The comparison of annual operation costs showed that heat pump operation cost is slightly lower than operation cost of biomass boiler. The analysis of above results shows that lower operation cost of heat pump in comparison with biomass boiler cost lets qualify heat pump as more economically justified only after 38 years of work. For both analysed devices, CO2 emission levels were determined. The considerations take into account the fact that heat pump consumes electricity. It is mostly generated through combustion of coal in Poland. The results show that in Poland biomass boiler can be described as not only more economically justified system but also as considerably more ecological.

Comparative analysis of heat pump and biomass boiler for small detached house heating

Science.gov (United States)

Olkowski, Tomasz; Lipiński, Seweryn; Olędzka, Aneta

2017-10-01

The purpose of the work is to answer the question - which of the two selected heat sources is more economically beneficial for small detached house: heat pump or biomass boiler fuelled with wood-pellets? The comparative analysis of these sources was carried out to discuss the issue. First, cost of both, equipment and operation of selected heat systems were analysed. Additionally, CO2 emission levels associated with these heat systems were determined. The comparative analysis of the costs of both considered heat systems showed that equipment cost of heat pump system is considerably bigger than the cost of biomass boiler system. The comparison of annual operation costs showed that heat pump operation cost is slightly lower than operation cost of biomass boiler. The analysis of above results shows that lower operation cost of heat pump in comparison with biomass boiler cost lets qualify heat pump as more economically justified only after 38 years of work. For both analysed devices, CO2 emission levels were determined. The considerations take into account the fact that heat pump consumes electricity. It is mostly generated through combustion of coal in Poland. The results show that in Poland biomass boiler can be described as not only more economically justified system but also as considerably more ecological.

Diffraction dissociation: thirty five years after

International Nuclear Information System (INIS)

Zotov, N.P.; Tsarev, V.A.

1988-01-01

Review of the basic results and stages of studying one of the most interesting phenomena in high energy physics-diffraction dissociation (DD) of hadrons is presented. The review contains complete information concerning the basic experimental results and the most ''set'' DD theoretical models. Though the discussion focuses primarily on considering a single nucleon DD, this still allows one to fully describe the basic features of the phenomenon under investigation. The last part of the review is devoted to the most notable results obtained during DD experimental investigation in the last five years, which have not been reflected in the earlier published reviews. Signs of excited system parton structure and pomeron are clearly found in the new experimental data. It is underlined that DD mechanism understanding is closely connected with the solution of the confinement problem in the strong interaction theory and requires further experimental and theoretical investigations

Twenty five years of fundamental theory

International Nuclear Information System (INIS)

Bell, J.S.

1980-01-01

In reviewing the last twenty five years in fundamental physics theory it is stated that there has been no revolution in this field. In the absence of gravitation, Lorentz invariance remains a requirement on fundamental laws. Einstein's theory of gravitation inspires increasing conviction on the astronomical scale. Quantum theory remains the framework for all serious effort in microphysics, and quantum electrodynamics remains the model of a fully articulated microphysical theory, completely successful in its domain. However,a number of ideas have appeared, of great theoretical interest and some phenomenological success, which may well contribute to the next decisive step. Recent work on the following topics is mentioned; gravitational radiation, singularites, black body radiation from black holes, gauge and hidden symmetry in quantum electrodynamics, the renormalization of electromagnetic and weak interaction theory, non-Abelian gauge theories, magnetic monopoles as the most striking example of solitons, and supersymmetry. (UK)

75 FR 34959 - Five-Year Review of Oil Pipeline Pricing Index

Science.gov (United States)

2010-06-21

...] Five-Year Review of Oil Pipeline Pricing Index June 15, 2010. AGENCY: Federal Energy Regulatory... comments on its five-year review of the oil pipeline pricing index established in Revisions to Oil Pipeline...-year review of the oil pricing index, the Commission adopted an index of PPI+1.3 for the five-year...

Test of a small domestic boiler using different pellets

International Nuclear Information System (INIS)

Dias, J.; Costa, M.; Azevedo, J.L.T.

2004-01-01

This paper presents results from an experimental study performed on a 13 kW th commercial domestic boiler using pellets as fuel. Four different types of pellets were used and, for each one, the boiler was tested as a function of its capacity and the fan regulation affecting excess air. Measurements were performed for boiler heat load, pellet consumption rate, flue-gas temperature and composition. Mass balances allowed the calculation of the flue-gas flow rate and associated heat losses. Losses from incomplete combustion have also been quantified. Under boiler steady-state conditions the flue-gas O 2 concentration changes with boiler load and ventilation due to the regulation scheme of the boiler. Flue-gas CO shows a minimum for values of O 2 in the flue-gases of about 13%. NO x emissions are independent of excess air for low values of nitrogen in the fuel whereas, for larger values, NO x emissions increase with the O 2 present in the combustion products. The fractional conversion of the pellet nitrogen into NO x is in line with literature data. The boiler start-up was characterised by the temperature evolution inside and above the bed showing the propagation of combustion in the bed during about 10 min. During boiler start-up, a maximum in CO emissions was observed which is associated with the maximum combustion intensity, as typified by the flue-gas O 2 concentration and temperature, regardless the pellet type. (Author)

78 FR 26616 - Draft NOAA Five Year Research and Development Plan

Science.gov (United States)

2013-05-07

... DEPARTMENT OF COMMERCE Draft NOAA Five Year Research and Development Plan AGENCY: National Oceanic and Atmospheric Administration (NOAA), Department of Commerce (DOC). ACTION: Draft NOAA Five Year Research and Development Plan for Public Review. SUMMARY: NOAA's draft Five Year Research and Development...

Development of pressurized internally circulating fluidized bed combustion technology; Kaatsu naibu junkan ryudosho boiler no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Ishihara, I [Center for Coal Utilization, Japan, Tokyo (Japan); Nagato, S; Toyoda, S [Ebara Corp., Tokyo (Japan)

1996-09-01

The paper introduced support research on element technology needed for the design of hot models of the pressurized internally circulating fluidized bed combustion boiler in fiscal 1995 and specifications for testing facilities of 4MWt hot models after finishing the basic plan. The support research was conduced as follows: (a) In the test for analysis of cold model fluidization, it was confirmed that each characteristic value of hot models is higher than the target value. Further, calculation parameters required for computer simulation were measured and data on the design of air diffusion nozzle for 1 chamber wind box were sampled. (b) In the CWP conveyance characteristic survey, it was confirmed that it is possible to produce CWP having favorable properties. It was also confirmed that favorable conveyability can be maintained even if the piping size was reduced down to 25A. (c) In the gas pressure reducing test, basic data required for the design of gas pressure reducing equipment were sampled. Specifications for the fluidized bed combustion boiler of hot models are as follows: evaporation amount: 3070kg/h, steam pressure: 1.77MPa, fuel supply amount: 600kg-coal/h, boiler body: cylinder shape water tube internally circulating fluidized bed combustion boiler. 4 refs., 4 figs.

Boiler: lossy compression of RNA-seq alignments using coverage vectors.

Science.gov (United States)

Pritt, Jacob; Langmead, Ben

2016-09-19

We describe Boiler, a new software tool for compressing and querying large collections of RNA-seq alignments. Boiler discards most per-read data, keeping only a genomic coverage vector plus a few empirical distributions summarizing the alignments. Since most per-read data is discarded, storage footprint is often much smaller than that achieved by other compression tools. Despite this, the most relevant per-read data can be recovered; we show that Boiler compression has only a slight negative impact on results given by downstream tools for isoform assembly and quantification. Boiler also allows the user to pose fast and useful queries without decompressing the entire file. Boiler is free open source software available from github.com/jpritt/boiler. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

30 CFR 57.13001 - General requirements for boilers and pressure vessels.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false General requirements for boilers and pressure... NONMETAL MINES Compressed Air and Boilers § 57.13001 General requirements for boilers and pressure vessels. All boilers and pressure vessels shall be constructed, installed, and maintained in accordance with...

30 CFR 56.13001 - General requirements for boilers and pressure vessels.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false General requirements for boilers and pressure... MINES Compressed Air and Boilers § 56.13001 General requirements for boilers and pressure vessels. All boilers and pressure vessels shall be constructed, installed, and maintained in accordance with the...

7 CFR 51.2833 - U.S. No. 1 Boilers.

Science.gov (United States)

2010-01-01

... 7 Agriculture 2 2010-01-01 2010-01-01 false U.S. No. 1 Boilers. 51.2833 Section 51.2833 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards...) Grades § 51.2833 U.S. No. 1 Boilers. U.S. No. 1 Boilers consists of onions which meet all the...

46 CFR 109.205 - Inspection of boilers and machinery.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Inspection of boilers and machinery. 109.205 Section 109... OPERATIONS Tests, Drills, and Inspections § 109.205 Inspection of boilers and machinery. The chief engineer or engineer in charge, before he assumes charge of the boilers and machinery of a unit shall inspect...

SRC burn test in 700-hp oil-designed boiler. Annex Volume C. Boiler emission report. Final technical report

Energy Technology Data Exchange (ETDEWEB)

1983-09-01

The Solvent-Refined Coal (SRC) test burn program was conducted at the Pittsburgh Energy Technology Center (PETC) located in Bruceton, Pa. One of the objectives of the study was to determine the feasibility of burning SRC fuels in boilers set up for fuel oil firing and to characterize emissions. Testing was conducted on the 700-hp oil-fired boiler used for research projects. No. 6 fuel oil was used for baseline data comparison, and the following SRC fuels were tested: SRC Fuel (pulverized SRC), SRC Residual Oil, and SRC-Water Slurry. Uncontrolled particulate emission rates averaged 0.9243 lb/10/sup 6/ Btu for SRC Fuel, 0.1970 lb/10/sup 6/ Btu for SRC Residual Oil, and 0.9085 lb/10/sup 6/ Btu for SRC-Water Slurry. On a lb/10/sup 6/ Btu basis, emissions from SRC Residual Oil averaged 79 and 78%, respectively, lower than the SRC Fuel and SRC-Water Slurry. The lower SRC Residual Oil emissions were due, in part, to the lower ash content of the oil and more efficient combustion. The SRC Fuel had the highest emission rate, but only 2% higher than the SRC-Water Slurry. Each fuel type was tested under variable boiler operating parameters to determine its effect on boiler emissions. The program successfully demonstrated that the SRC fuels could be burned in fuel oil boilers modified to handle SRC fuels. This report details the particulate emission program and results from testing conducted at the boiler outlet located before the mobile precipitator take-off duct. The sampling method was EPA Method 17, which uses an in-stack filter.

CFD modeling of ash deposition for co-combustion of MBM with coal in a tangentially fired utility boiler

NARCIS (Netherlands)

Taha, T.J.; Stam, A.F.; Stam, K.; Brem, Gerrit

2013-01-01

Ash deposition is one of the main challenges that needs to be tackled in response to increased percentage of biomass co-firing in pulverized fuel boilers. In this study, a model has been developed to investigate the slagging behavior of meat and bone meal (MBM) at higher co-firing rates in the

THREE-STAGE COMBUSTION (REBURNING) ON A FULL SCALE OPERATING BOILER IN THE U.S.S.R.

Science.gov (United States)

The report gives results of a program to complete preliminary design of a three- stage combustion (reburn) system for nitrogen oxide (NOx) emissions control on an operating boiler in the U. S.S. R. he program to design the reburn system consisted of five tasks: visiting the Ladyz...

46 CFR 62.35-20 - Oil-fired main boilers.

Science.gov (United States)

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Oil-fired main boilers. 62.35-20 Section 62.35-20... AUTOMATION Requirements for Specific Types of Automated Vital Systems § 62.35-20 Oil-fired main boilers. (a) General. (1) All main boilers, regardless of intended mode of operation, must be provided with the...

Five-Yearly Review 2010 : Confirmation that our salaries are going downhill

CERN Multimedia

Staff Association

2010-01-01

A general review of our financial and social conditions takes place every five years: “the five-yearly review”, whose principles and procedures are described in Annex A1 of the Staff Rules and Regulations. The purpose of the five-yearly review is to ensure that the financial and social conditions offered by the Organization allow it to recruit and retain from all its Member States staff members of the highest competence and integrity required for the execution of its mission. The five-yearly review must include basic remuneration (the basic salaries of staff members, the stipends of fellows, and the subsistence allowances of associated members of the personnel) and may include any other financial or social conditions. Start of the 2010 five-yearly review and data collection As we wrote in Echo no. 80, CERN Council approved the document CERN/2862 for the 2010 five-yearly review (hereinafter 2010 5YR) at its meeting on 19th June 2009. This was the Management’s proposal which...

40 CFR 266.110 - Waiver of DRE trial burn for boilers.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 26 2010-07-01 2010-07-01 false Waiver of DRE trial burn for boilers... HAZARDOUS WASTE MANAGEMENT FACILITIES Hazardous Waste Burned in Boilers and Industrial Furnaces § 266.110 Waiver of DRE trial burn for boilers. Boilers that operate under the special requirements of this section...

Solved and unsolved problems in boiler systems. Learning from accidents

International Nuclear Information System (INIS)

Ozawa, Mamoru

2000-01-01

This paper begins with a brief review on the similarity law of conventional fossil-fuel-fired boilers. The concept is based on the fact that the heat release due to combustion in the furnace is restricted by the furnace volume but the heat absorption is restricted by the heat transfer surface area. This means that a small-capacity boiler has relatively high specific furnace heat release rate, about 10 MW/m 3 , and on the contrary a large-capacity boiler has lower value. The surface-heat-flux limit is mainly dominated by the CHF inside the water-wall tubes of the boiler furnace, about 350 kW/m 2 . This heat-flux limit is almost the same order independently on the capacity of boilers. For the safety of water-walls, it is essential to retain suitable water circulation, i.e. circulation ratio and velocity of water. This principle is a common knowledge of boiler designer, but actual situation is not the case. Newly designed boilers often suffer from similar accidents, especially burnout due to circulation problems. This paper demonstrates recent accidents encountered in practical boilers, and raises problems of rather classical but important two-phase flow and heat transfer. (author)

Slagging in a pulverised-coal-fired boiler

Energy Technology Data Exchange (ETDEWEB)

Devir, G.P.; Pohl, J.H.; Creelman, R.A. [University of Queensland, St. Lucia, Qld. (Australia). Dept. of Chemical Engineering

2000-07-01

This paper describes a technique to evaluate the severity of slagging of a coal in a pulverised-coal-fired boiler. There are few data in the literature on the nature of in-situ boiler slags, their rate of growth and/or their strength properties relevant to sootblowing. The latter is thought to be of more concern to boiler operators and gives rise to the significance of selecting suitable strength tests. As well as standardised methods for characterising pulverised coal performance in a boiler, several novel and less popular techniques are discussed in detail. A suite of three sub-bituminous coals from the Callide Coalfields, Biloela (600 km north of Brisbane), has been selected for slagging tests in the 350 MW{sub e} units of Callide 'B' power station. Disposable air-cooled mild steel slagging probes have been constructed to simulate the conditions for deposit formation in the boiler region. To date, tests for one of these coals has been completed and preliminary results are presented. Once testing for the remaining coals has been completed, it is anticipated that the differences exhibited in deposit growth and strength may be correlated with typical variations in physical and chemical properties of the pulverised coal.

Twenty-five years of modeling multiphase flow and heat transfer

International Nuclear Information System (INIS)

Lyczkowski, R.W.

1999-01-01

This presentation will cover some of the highlights of multiphase modeling in collaboration with Professor Dimitri Gidaspow (DG) over the last roughly twenty-five years. It all started in 1972 in Idaho Falls with Charles Solbrig, who planned and initiated a project for the former USAEC to develop a computer code to replace RELAP4 to analyze the loss of coolant accident (LOCA). DG spent his sabbatical on the project in 1973. One highlight was the discovery of complex characteristics, the implications of which are still pondered by some. Fluidization research began in 1978 when the author collaboratively developed a step-by-step building-block approach to understanding the hydrodynamics of fluidized beds, an approach closely coupled to validation experiments. A grant from the USDOE to study solids circulation around a jet in a fluidized bed was awarded to DG in 1978. Following that, grants from GRI, NSF, and a contract from Westinghouse Electric Corp. allowed the early work to continue. Progress was slow since computer costs were high. Subsequent continuing support from the USDOE, NSF, EPRI, and industry has allowed research to continue, as has his collaboration. A highlight of this collaboration was the development of the monolayer energy dissipation (MED) erosion model. Multiphase flow and fluidization theory took quantum leaps with the publication of DG's Multiphase Flow and Fluidization: Continuum and Kinetic Theory Descriptions (MFF), Academic Press, San Diego (1994), for which there is essentially no competition. Only the late Professor S.L. Soo's Particulates and Continuum: Multiphase Fluid Dynamics, Hemisphere Publishing Corp., New York (1989), a textbook version of the classic monograph Multiphase Fluid Dynamics, Science Press, Beijing, China (1990), comes close. In MFF, the kinetic theory of granular flow has evolved as a potentially viable adjunct to the continuum multiphase theory, of which fluidization is one important manifestation. It must be

Outcome of the 2015 five-yearly review: decision time

CERN Multimedia

Staff Association

2015-01-01

To ensure that CERN remains a centre of excellence in the field of fundamental research, the Organization verifies every five years with the help of a Five-yearly review procedure whether the financial and social conditions which it proposes to its staff allow it to recruit and retain Staff Members of the highest competence and integrity required for the execution of its mission and coming from all Member States. For Fellows these conditions should remain attractive compared with those in comparable research institutions, while for Associated members of personnel the conditions should allow it to host them in its research facilities taking into account the highest cost-of-living level in the local region of the Organization. Annex A1 of the CERN Staff Rules prescribes the principles of how to manage this Five-Yearly process. Getting ready In order to prepare the 2015 Five-yearly review and to help define the topics which had to be decided by the CERN Council in June 2014, the Staff Association has organized ...

Fire-side corrosion in power-station boilers

Energy Technology Data Exchange (ETDEWEB)

Cutler, A J.B.; Flatley, T; Hay, K A

1978-10-01

The steel tubing of a modern power-station boiler operates at up to 650/sup 0/C (a dull red heat) in the very corrosive environment produced by the combustion gases and ash particles. Within the tubes, whose walls are around 5mm thick, 2000 tons of steam are generated per hour at temperatures up to 565/sup 0/C and pressures up to 170 bar. Several forms of metal corrosion may occur on the fireside surface of these tubes and on other boiler components. The designed 20-year operating life of the stainless-steel superheater and reheater tubes can be much reduced at temperatures above 600/sup 0/C by attack from molten salts formed beneath the deposited ash on the upstream tube surfaces. Mild steel evaporator tubes lining the furnace wall may suffer similarly if flame impingement allows the local release of volatile chlorine compounds from coal particles on the tube surface. Uncooled metal components supporting and aligning the boiler tubes may reach 1000/sup 0/C and are particularly susceptible to corrosion. CEGB research effort has been applied to quantify the rate of corrosion and to obtain an understanding of the complex corrosion mechanisms, so that ways of minimizing or preventing their occurrence may be found. These include the optimization of the combustion chemistry, design modifications such as shielding certain vulnerable tubes, and the selection of improved alloys and the use of ''co-extruded'' tubing.

46 CFR 52.25-5 - Miniature boilers (modifies PMB-1 through PMB-21).

Science.gov (United States)

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Miniature boilers (modifies PMB-1 through PMB-21). 52.25... ENGINEERING POWER BOILERS Other Boiler Types § 52.25-5 Miniature boilers (modifies PMB-1 through PMB-21). Miniature boilers must meet the applicable provisions in this part for the boiler type involved and the...

Failure analyses and weld repair of boiler feed water pumps

Energy Technology Data Exchange (ETDEWEB)

Vulpen, R van [KemaPower Generation, Arnhem (Netherlands)

1999-12-31

During a regular inspection of the Boiler Auxiliaries at one of the Dutch Electricity Production Companies serious cracks were found in the cover and casings of the feed water circulation pumps in two units after 108.000 and 122.000 hours of boiler operation. Kema Laboratories carried out Failure analyses on boat samples at the cracked areas. Corrosion fatigue cracking was found on the inner side of the GS-24CrNiMo325 casing. Shop Weld repairs were carried out using a newly developed mechanized Plasma Welding Technique. The repaired feed water circulation pumps showed no problems alter several years of operation. The costs of repair were substantially lower than the costs of replacement. (orig.) 3 refs.

Failure analyses and weld repair of boiler feed water pumps

Energy Technology Data Exchange (ETDEWEB)

Vulpen, R. van [KemaPower Generation, Arnhem (Netherlands)

1998-12-31

During a regular inspection of the Boiler Auxiliaries at one of the Dutch Electricity Production Companies serious cracks were found in the cover and casings of the feed water circulation pumps in two units after 108.000 and 122.000 hours of boiler operation. Kema Laboratories carried out Failure analyses on boat samples at the cracked areas. Corrosion fatigue cracking was found on the inner side of the GS-24CrNiMo325 casing. Shop Weld repairs were carried out using a newly developed mechanized Plasma Welding Technique. The repaired feed water circulation pumps showed no problems alter several years of operation. The costs of repair were substantially lower than the costs of replacement. (orig.) 3 refs.

Thermal design of horizontal tube boilers: numerical and experimental investigation

International Nuclear Information System (INIS)

Roser, Robert

1999-01-01

This work concerns the thermal design of kettle re-boilers. Current methods are highly inaccurate, regarded to the correlations for external heat transfer coefficient at one tube scale, as well as to two-phase flow modelling at boiler scale. The aim of this work is to improve these thermal design methods. It contains an experimental investigation with typical operating conditions of such equipment: an hydrocarbon (n-pentane) with low mass flux. This investigation has lead to characterize the local flow pattern through void fraction measurements and, from this, to develop correlations for void fraction, pressure drop and heat transfer coefficient. The approach is original, since the developed correlations are based on the liquid velocity at minimum cross section area between tubes, as variable characterizing the hydrodynamic effects on pressure drop and heat transfer coefficient. These correlations are shown to give much better results than those suggested up to now in the literature, which are empirical transpositions from methods developed for inside tube flows. Furthermore, the numerical code MC3D has been applied using the correlations developed in this work, leading to a modelization of the two-phase flow in the boiler, which is a significant progress compared to current simplified methods. (author) [fr

Experimental determination of temperatures of the inner wall of a boiler combustion chamber for the purpose of verification of a CFD model

Directory of Open Access Journals (Sweden)

Petr Trávníček

2011-01-01

Full Text Available The paper focuses on the non-destructive method of determination of temperatures in the boiler combustion chamber. This method proves to be significant mainly as regards CFD (Computational Fluid Dynamics simulations of combustion processes, in case of which it is subsequently advisable to verify the data calculated using CFD software application with the actually measured data. Verification of the method was based on usage of reference combustion equipment (130 kW which performs combustion of a mixture of waste sawdust and shavings originating in the course of production of wooden furniture. Measuring of temperatures inside the combustion chamber is – considering mainly the high temperature values – highly demanding and requires a special type of temperature sensors. Furthermore, as regards standard operation, it is not possible to install such sensors without performing structural alterations of the boiler. Therefore, for the purpose of determination of these temperatures a special experimental device was constructed while exploiting a thermal imaging system used for monitoring of the surface temperature of outer wall of the reference boiler. Temperatures on the wall of the boiler combustion chamber were determined on the basis of data measured using the experimental device as well as data from the thermal imaging system. These values might serve for verification of the respective CFD model of combustion equipment.

CFD modeling of small biomass-fired boilers, second stage; CFD-modellering av mindre biobraenslepannor, etapp 2

Energy Technology Data Exchange (ETDEWEB)

Loennermark, A. [Swedish National Testing and Research Inst., Boraas (Sweden); Leckner, B. [Chalmers Univ. of Techn., Goeteborg (Sweden). Dept. of Energy Technology

2001-11-01

The purpose of the project is to study how the design of the gas combustion chamber in a small boiler for biomass affects the emissions and how computer simulations can be used to decrease harmful emissions. The aim of the first part of the project was to investigate how phenomena and processes, important for the combustion, depend on various parameters. Within the frame of that part the temperature distribution, the flow pattern and the mixing processes have been studied. In the second part the combustion and the different reactions have been studied. A number of well-equipped combustion experiments in a small biomass-fired boiler have also been conducted to obtain better information about the boundary conditions. The results have been used to verify the simulations. The gas combustion chamber of a modern boiler using down draught firing has been simulated by using two Computational Fluid Dynamics codes, SOFIE and FLUENT. The results from the simulations show that with literature values for the reaction parameters, the reaction rates are controlled by mixing. This means that the reactions are fast and all the CO and the hydrocarbons were consumed. By varying the activation energy, it is possible to reach data that are more comparable with experimental data. The effects of the bowl in the gas combustion chamber on the combustion and mixing are discussed. The effects of the temperature and the radiation are also presented.

75 FR 80300 - Five-Year Review of Oil Pipeline Pricing Index

Science.gov (United States)

2010-12-22

...] Five-Year Review of Oil Pipeline Pricing Index Issued December 16, 2010. AGENCY: Federal Energy... five-year review of the oil pricing index, established in Order No. 561. After consideration of the... period commencing July 1, 2011. \\1\\ Five-Year Review of Oil Pipeline Pricing Index, 75 FR 34959 (June 21...

Statistical modeling of an integrated boiler for coal fired thermal power plant.

Science.gov (United States)

Chandrasekharan, Sreepradha; Panda, Rames Chandra; Swaminathan, Bhuvaneswari Natrajan

2017-06-01

The coal fired thermal power plants plays major role in the power production in the world as they are available in abundance. Many of the existing power plants are based on the subcritical technology which can produce power with the efficiency of around 33%. But the newer plants are built on either supercritical or ultra-supercritical technology whose efficiency can be up to 50%. Main objective of the work is to enhance the efficiency of the existing subcritical power plants to compensate for the increasing demand. For achieving the objective, the statistical modeling of the boiler units such as economizer, drum and the superheater are initially carried out. The effectiveness of the developed models is tested using analysis methods like R 2 analysis and ANOVA (Analysis of Variance). The dependability of the process variable (temperature) on different manipulated variables is analyzed in the paper. Validations of the model are provided with their error analysis. Response surface methodology (RSM) supported by DOE (design of experiments) are implemented to optimize the operating parameters. Individual models along with the integrated model are used to study and design the predictive control of the coal-fired thermal power plant.

A rule-based industrial boiler selection system

NARCIS (Netherlands)

Tan, C.F.; Khalil, S.N.; Karjanto, J.; Tee, B.T.; Wahidin, L.S.; Chen, W.; Rauterberg, G.W.M.; Sivarao, S.; Lim, T.L.

2015-01-01

Boiler is a device used for generating the steam for power generation, process use or heating, and hot water for heating purposes. Steam boiler consists of the containing vessel and convection heating surfaces only, whereas a steam generator covers the whole unit, encompassing water wall tubes,

Techniques for measurement of heat flux in furnace waterwalls of boilers and prediction of heat flux – A review

International Nuclear Information System (INIS)

Sankar, G.; Chandrasekhara Rao, A.; Seshadri, P.S.; Balasubramanian, K.R.

2016-01-01

Highlights: • Heat flux measurement techniques applicable to boiler water wall are elaborated. • Applications involving heat flux measurement in boiler water wall are discussed. • Appropriate technique for usage in high ash Indian coal fired boilers is required. • Usage of chordal thermocouple is suggested for large scale heat flux measurements. - Abstract: Computation of metal temperatures in a furnace waterwall of a boiler is necessary for the proper selection of tube material and thickness. An adequate knowledge of the heat flux distribution in the furnace walls is a prerequisite for the computation of metal temperatures. Hence, the measurement of heat flux in a boiler waterwall is necessary to arrive at an optimum furnace design, especially for high ash Indian coal fired boilers. Also, a thoroughly validated furnace model will result in a considerable reduction of the quantum of experimentation to be carried out. In view of the above mentioned scenario, this paper reviews the research work carried out by various researchers by experimentation and numerical simulation in the below mentioned areas: (i) furnace modeling and heat flux prediction, (ii) heat flux measurement techniques and (iii) applications of heat flux measurements.

Increase of efficiency and reliability of liquid fuel combustion in small-sized boilers

Science.gov (United States)

Roslyakov, P. V.; Proskurin, Yu V.; Ionkin, I. L.

2017-11-01

One of the ways to increase the efficiency of using fuels is to create highly efficient domestic energy equipment, in particular small-sized hot-water boilers in autonomous heating systems. Increasing the efficiency of the boiler requires a reduction in the temperature of the flue gases leaving, which, in turn, can be achieved by installing additional heating surfaces. The purpose of this work was to determine the principal design solutions and to develop a draft design for a high-efficiency 3-MW hot-water boiler using crude oil as its main fuel. Ensuring a high efficiency of the boiler is realized through the use of an external remote economizer, which makes it possible to reduce the dimensions of the boiler, facilitate the layout of equipment in a limited size block-modular boiler house and virtually eliminate low-temperature corrosion of boiler heat exchange surfaces. In the article the variants of execution of the water boiler and remote economizer are considered and the preliminary design calculations of the remote economizer for various schemes of the boiler layout in the Boiler Designer software package are made. Based on the results of the studies, a scheme was chosen with a three-way boiler and a two-way remote economizer. The design of a three-way fire tube hot water boiler and an external economizer with an internal arrangement of the collectors, providing for its location above the boiler in a block-modular boiler house and providing access for servicing both a remote economizer and a hot water boiler, is proposed. Its mass-dimensional and design parameters are determined. In the software package Boiler Designer thermal, hydraulic and aerodynamic calculations of the developed fire tube boiler have been performed. Optimization of the boiler design was performed, providing the required 94% efficiency value for crude oil combustion. The description of the developed flue and fire-tube hot water boiler and the value of the main design and technical and

Application of GPRS and GIS in Boiler Remote Monitoring System

OpenAIRE

Hongchao Wang; Yifeng Wu

2012-01-01

Application of GPRS and GIS in boiler remote monitoring system was designed in this paper by combining the advantage of GPRS and GIS in remote data transmission with configuration monitoring technology. The detail information of the operating conditions of the industrial boiler can be viewed by marking the location of boiler on the electronic map dynamically which can realize the unified management for industrial boiler of a region or city conveniently. Experimental application show that the ...

Economic evaluation of a coal fired boiler

International Nuclear Information System (INIS)

Briem, J.J.

1983-01-01

This paper provides basic information on boiler economics which will assist steam users in analyzing the feasibility of using coal to generate steam - in either new or existing facilities. The information presented covers boilers ranging in size from 10,000 to 100,000 pounds per hour steaming capacity

Biomass boiler conversion potential in the eastern United States

Science.gov (United States)

Charles D. Ray; Li Ma; Thomas Wilson; Daniel Wilson; Lew McCreery; Janice K. Wiedenbeck

2013-01-01

The U.S. is the world's leading consumer of primary energy. A large fraction of this energy is used in boiler installations to generate steam and hot water for heating applications. It is estimated there are total 163,000 industrial and commercial boilers in use in the United States of all sizes. This paper characterizes the commercial and industrial boilers in...

9 CFR 91.22 - Protection from heat of boilers and engines.

Science.gov (United States)

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Protection from heat of boilers and... Protection from heat of boilers and engines. No animals shall be stowed along the alleyways leading to the engine or boiler rooms unless the sides of said engine or boiler rooms are covered by a tongue and groove...

Recovery Act: Oxy-Combustion Technology Development for Industrial-Scale Boiler Applications

Energy Technology Data Exchange (ETDEWEB)

Levasseur, Armand

2014-01-01

This Topical Report outlines guidelines and key considerations for design and operation of pulverized coal-fired boilers for oxy-combustion. The scope addressed includes only the boiler island, not the entire oxy-fired CO{sub 2} capture plant. These guidelines are primarily developed for tangential-fired boilers and focus on designs capable of dual air and oxy-fired operation. The guidelines and considerations discussed are applicable to both new units and existing boiler retrofits. These guidelines are largely based on the findings from the extensive 15 MW{sub th} pilot testing and design efforts conducted under this project. A summary level description is provided for each major aspect of boiler design impacted by oxy-combustion, and key considerations are discussed for broader application to different utility and industrial designs. Guidelines address the boiler system arrangement, firing system, boiler thermal design, ducting, materials, control system, and other key systems.

Boiler for combustion fuel in a fluidized bed

Directory of Open Access Journals (Sweden)

Laković Mirjana S.

2015-01-01

Full Text Available Fuel combustion in fluidized bed combustion is a process that is current and which every day gives more attention and there are many studies that have been closely associated with this technology. This combustion technology is widespread and constantly improving the range of benefits it provides primarily due to reduced emissions. This paper presents the boilers for combustion in a fluidized bed, whit characteristics and advantages. Also is shown the development of this type of boilers in Republic of Serbia. In this paper is explained the concept of fluidized bed combustion. Boilers for this type of combustion can be improved and thereby increase their efficiency level. More detailed characteristics are given for boilers with bubbling and circulating fluidized bed as well as their mutual comparison.

High gradient magnetic filters for boiler water treatment

International Nuclear Information System (INIS)

Harland, J.R.; Nichols, R.M.

1977-01-01

Heavy metal oxide suspended solids in those steam condensates recycled to the boilers produce buildup within the boiler tubes which can lead to unequal and reduced heat transfer efficiency, and indirectly, to boiler tube failures. Recommended reductions in such suspended solids in feedwater to the economizers of modern high pressure boilers to levels of under 10 ppb have been published. The industrially-available SALA-HGMF magnetic filter has achieved these desired suspended solids levels in treating steam condensates. The high gradient magnetic filter has been shown in pilot tests to achieve and even exceed the recommended low level suspended solids in a practical and efficient industrial system. Such electromagnetic filters, when combined with good system chemistry, have achieved low single number parts per billion levels of several heavy metals with very high single-pass efficiencies

Computational fluid dynamics (CFD) modelling of coal/biomass co-firing in pulverised fuel boilers

Energy Technology Data Exchange (ETDEWEB)

Moghtaderi, B.; Meesri, C. [University of Newcastle, Callaghan, NSW (Australia). CRC for Coal in Sustainable Development, Dept. of Chemical Engineering

2002-07-01

The present study is concerned with computational fluid dynamics (CFD) modelling of coal/biomass blends co-fired under conditions pertinent to pulverised fuel (PF) boilers. The attention is particularly focused on the near burner zone to examine the impact of biomass on the flame geometry and temperature. The predictions are obtained by numerical solution of the conservation equations for the gas and particle phases. The gas phase is solved in the Eulerian domain using steady-state time-averaged Navier-Stokes equations while the solution of the particle phase is obtained from a series of Lagrangian particle tracking equations. Turbulence is modelled using the {kappa}-{epsilon} and Reynolds Stress models. The comparison between the predictions and experimental measurement reported in the literature resulted in a good agreement. Other influences of biomass co-firing are observed for fuel devolatilisation and burnout. 19 refs., 6 figs.

Fire-Side Corrosion: A Case Study of Failed Tubes of a Fossil Fuel Boiler

Directory of Open Access Journals (Sweden)

Majid Asnavandi

2017-01-01

Full Text Available The failures of superheater and reheater boiler tubes operating in a power plant utilizing natural gas or mazut as a fuel have been analysed and the fire-side corrosion has been suggested as the main reason for the failure in boiler tubes. The tubes have been provided by a fossil fuel power plant in Iran and optical and electron microscopy investigations have been performed on the tubes as well as the corrosion products on their surfaces. The results showed that the thickness of the failed tubes is not uniform which suggests that fire-side corrosion has happened on the tubes. Fire-side corrosion is caused by the reaction of combustion products with oxide layers on the tube surface resulting in metal loss and consequently tubes fracture. However, the tubes corrosion behaviour did not follow the conventional models of the fire-side corrosion. Given that, using the corrosion monitoring techniques for these boiler tubes seems essential. As a result, the thickness of the boiler tubes in different parts of the boiler has been recorded and critical points are selected accordingly. Such critical points are selected for installation of corrosion monitoring probes.

Fracture analysis of tube boiler for physical explosion accident.

Science.gov (United States)

Kim, Eui Soo

2017-09-01

Material and failure analysis techniques are key tools for determining causation in case of explosive and bursting accident result from material and process defect of product in the field of forensic science. The boiler rupture generated by defect of the welding division, corrosion, overheating and degradation of the material have devastating power. If weak division of boiler burner is fractured by internal pressure, saturated vapor and water is vaporized suddenly. At that time, volume of the saturated vapor and water increases up to thousands of volume. This failure of boiler burner can lead to a fatal disaster. In order to prevent an explosion and of the boiler, it is critical to introduce a systematic investigation and prevention measures in advance. In this research, the cause of boiler failure is investigated through forensic engineering method. Specifically, the failure mechanism will be identified by fractography using scanning electron microscopes (SEM) and Optical Microscopes (OM) and mechanical characterizations. This paper presents a failure analysis of household welding joints for the water tank of a household boiler burner. Visual inspection was performed to find out the characteristics of the fracture of the as-received material. Also, the micro-structural changes such as grain growth and carbide coarsening were examined by optical microscope. Detailed studies of fracture surfaces were made to find out the crack propagation on the weld joint of a boiler burner. It was concluded that the rupture may be caused by overheating induced by insufficient water on the boiler, and it could be accelerated by the metal temperature increase. Copyright © 2017 Elsevier B.V. All rights reserved.

Static stability characteristics of the boilers at Oldbury nuclear power station

International Nuclear Information System (INIS)

Paynter, R.J.; Rea, J.

1986-01-01

The cause of an intermittent load loss at Oldbury Nuclear Power Station is shown to be the high sensitivity of boiler performance to the imposed spatial distribution of boiler gas inlet temperature. This high sensitivity is demonstrated to be a function of the inherent static stability characteristics of the boilers. The installation of orifice plates with a high flow resistance into the feed pipework to the half boilers has greatly reduced the boiler sensitivity and eliminated the intermittent load loss so that, on average, higher electrical generation is obtained from the station. (author)

Feasibility of recovery boiler in paper and pulp industry

International Nuclear Information System (INIS)

Rashid, H.

2010-01-01

in this paper feasibility of recovery boiler in terms of economics and environmental impacts in studied. Recovery boilers are employed in the pulp and paper industry where the cooking agent is recovered by burning black liquor. Cooking agent is exhausted due to the absorption of lignin (a burnable component) in cooking agent in the process of straw cooking. The process of recovery boiler is to remove lignin by combustion from black liquor, and heat is produced during the combustion of lignin which is used to produce steam. Recovery boiler is economical as it is recovering valuable chemicals and steam is produced as a byproduct. Steam from recovery boiler is also used for concentrating weak black liquor to concentrated black liquor recovering 50% of the utility water being used at the plant. The regenerated water in the form of foul condensate is reused in the process. The recovery of hazardous chemicals also reduces load of environmental pollution. Which otherwise can pollute the water reservoirs, and regeneration of water makes it environmentally friendly plant. Construction and challenges in operation of recovery boiler such as smelt-water explosion are also discussed in this paper. (author)

Significant achievements in '10th five-year plan' period and primary guidance in '11th five-year plan' period on uranium exploration

International Nuclear Information System (INIS)

Zhang Jindai; Li Youliang; Jian Xiaofei; Peng Xinjian; Jiang Deying

2007-01-01

During the '10th five-year-plane' period, uranium resource had attracted high attention and concentration from related organization of the CCPC and the central government because of the state's manifestation on the development goal for nuclear power, efforts on uranium research and exploration were intensified accordingly. In that five years, both uranium exploration, regional assessment and prognostication for the Mesozoic-Cenozoic basin in North China and research on uranium metallogeny theory and prospecting method had made fairly great progress and reached important fruits. Due to the improvement of prospecting theory and technology for ISL amenable sandstone hosted U-deposits, uranium exploration efficiency was great enhanced and had prompted the sustainable development for China's uranium exploration. This paper have briefly expounded the general deploy for the uranium geology research and exploration in the '11th five-year plan' period. (authors)

Process for start-up and slack period operation of fully charged boilers, e. g. of coal pressure gasification plants, and boiler system to carry out the process

Energy Technology Data Exchange (ETDEWEB)

Meyer-Kahrweg, H

1978-10-19

For the start-up and slack period of fully charged boilers hot water of e.g. 180/sup 0/C from a high pressure heater which is fed by a start-up boiler is used. In the first instance the boiler, its preheater and the vaporizer are filled with hot water from the start-up boiler until a medium water level is obtained. Subsequently water from the water separator is recycled through the preheater and the boiler by forced circulation and it is heated up to the hot water temperature by the start-up boiler. After the desired temperature has been reached the pressure combustion is ignited and the circulation through the preheater is interrupted by reversing to direct feed back. A considerable shortening of the start-up time is achieved because no heat is released to the condensation water in the boiler system as is done usually.

High Efficiency - Reduced Emissions Boiler Systems for Steam, Heat, and Processing

Science.gov (United States)

2012-07-01

enable energy saving necessary for obtaining Energy Star certification for the whole boiler system. Widespread boiler control updates could be possible...adaptability to different boiler and oil/gas burner configurations, and extensibility to operation with nonconventional fuels (e.g., biogas and syngas...typically operating below or slightly above 80%. Higher efficiency improvements can certainly be obtained via boiler replacement and adoption of

Boiler burden reduced at Bedford site.

Science.gov (United States)

Horsley, Chris

2011-10-01

With the NHS aiming to reduce its 2007 carbon footprint by 10% by 2015, Chris Horsley, managing director of Babcock Wanson UK, a provider of industrial boilers and burners, thermal oxidisers, air treatment, water treatment, and associated services, looks at how one NHS Trust has approached the challenge, and considerably reduced its carbon emissions, by refurbishing its boiler house and moving from oil to gas-fired steam generation.

Increasing the efficiency of the condensing boiler

Science.gov (United States)

Zaytsev, ON; Lapina, EA

2017-11-01

Analysis of existing designs of boilers with low power consumption showed that the low efficiency of the latter is due to the fact that they work in most cases when the heating period in the power range is significantly less than the nominal power. At the same time, condensing boilers do not work in the most optimal mode (in condensing mode) in the central part of Russia, a significant part of their total operating time during the heating season. This is due to existing methods of equipment selection and joint operation with heating systems with quantitative control of the coolant. It was also revealed that for the efficient operation of the heating system, it is necessary to reduce the inertia of the heat generating equipment. Theoretical patterns of thermal processes in the furnace during combustion gas at different radiating surfaces location schemes considering the influence of the very furnace configuration, characterized in that to reduce the work condensing boiler in conventional gas boiler operation is necessary to maintain a higher temperature in the furnace (in the part where spiral heat exchangers are disposed), which is possible when redistributing heat flow - increase the proportion of radiant heat from the secondary burner emitter allow Perey For the operation of the condensing boiler in the design (condensation) mode practically the entire heating period.

Apparatus and method of controlling the thermal performance of an oxygen-fired boiler

Science.gov (United States)

Levasseur, Armand A.; Kang, Shin G.; Kenney, James R.; Edberg, Carl D.

2017-09-05

Disclosed herein is a method of controlling the operation of an oxy-fired boiler; the method comprising combusting a fuel in a boiler; producing a heat absorption pattern in the boiler; discharging flue gases from the boiler; recycling a portion of the flue gases to the boiler; combining a first oxidant stream with the recycled flue gases to form a combined stream; splitting the combined stream into several fractions; and introducing each fraction of the combined stream to the boiler at different points of entry to the boiler.

Measurements and numerical simulations for optimization of the combustion process in a utility boiler

Energy Technology Data Exchange (ETDEWEB)

Vikhansky, A.; Bar-Ziv, E. [Ben-Gurion Univ. of the Negev, Dept. of Biotechnology and Environmental Engineering, Beer-Sheva (Israel); Chudnovsky, B.; Talanker, A. [Israel Electric Corp. (IEC),, Mechanical Systems Div., Haifa (Israel); Eddings, E.; Sarofim, A. [Reaction Engineering International, Salt Lake City, UT (United States); Utah Univ., Dept. of Chemical and Fuel Engineering, Salt Lake City, UT (United States)

2004-07-01

A three-dimensional computational fluid dynamics code was used to analyse the performance of 550MW pulverized coal combustion opposite a wall-fired boiler (of IEC) at different operation modes. The main objective of this study was to prove that connecting plant measurements with three-dimensional furnace modelling is a cost-effective method for design, optimization and problem solving in power plant operation. Heat flux results from calculations were compared with measurements in the boiler and showed good agreement. Consequently, the code was used to study hydrodynamic aspects of air-flue gases mixing in the upper part of the boiler. It was demonstrated that effective mixing between flue gases and overfire air is of essential importance for CO reburning. From our complementary experimental-numerical effort, IEC considers a possibility to improve the boiler performance by replacing the existing OFA nozzles by those with higher penetration depth of the air jets, with the aim to ensure proper mixing to achieve better CO reburning. (Author)

Wood fuelled boiler operating costs

International Nuclear Information System (INIS)

Sandars, D.L.

1995-01-01

This report is a management study into the operating costs of wood-fired boilers. Data obtained from existing wood-fired plant has been analysed and interpreted using the principles of machinery management and the science that underlies the key differences between this fuel and any other. A set of budgeting principles has been developed for the key areas of labour requirement, insurance, maintenance and repair and electricity consumption. Other lesser cost centres such as the provision of shelter and the effects of neglect and accidents have also been considered, and a model constructed. (author)

Cross connecting absorber module inlets of multiple boiler units

International Nuclear Information System (INIS)

Cirillo, A.J.; Sperber, P.K.; Belavadi, V.N.; Mukherji, A.

1991-01-01

The retrofitting of scrubbers downstream of existing balanced draft boilers is often accomplished by the addition of induced draft (ID) booster fans. By creating a common plenum between the ID fans and the ID booster fans of two or more boiler-absorber trains, absorber module capacity may be shared among multiple boiler units. At Harrison Power Station, three (3) 4,900,000 lb/hour boilers (640 MWe Gross) will be linked through a common plenum. This sharing capability precludes the need to add standby module capacity, thereby saving capital dollars and keeping project critical path schedules, which typically run through absorber procurement and construction, to a minimum. Through damper placement in the ductwork cross connections, unitized boiler-absorber module operation or common plenum operation may be obtained, thus providing both operational flexibility and reliability. Additionally, open plenum operation allows the removal of an absorber unit from service, while keeping its associated boiler on line, thereby precluding 'cold starts' and maintaining overall unit availabilities. As either unitized or common plenum operation is possible with the cross connection, the furnace draft control systems of each boiler must be examined for varying load operation and trip conditions. This paper addresses the means by which to analyze such cross connection operational scenarios while maintaining compliance with furnace flame out safety guidelines, and will discuss the physical design considerations, ramifications and benefits of same, with select emphasis on what is being implemented at the Harrison Power Station

Supercritical boiler material selection using fuzzy analytic network process

Directory of Open Access Journals (Sweden)

Saikat Ranjan Maity

2012-08-01

Full Text Available The recent development of world is being adversely affected by the scarcity of power and energy. To survive in the next generation, it is thus necessary to explore the non-conventional energy sources and efficiently consume the available sources. For efficient exploitation of the existing energy sources, a great scope lies in the use of Rankin cycle-based thermal power plants. Today, the gross efficiency of Rankin cycle-based thermal power plants is less than 28% which has been increased up to 40% with reheating and regenerative cycles. But, it can be further improved up to 47% by using supercritical power plant technology. Supercritical power plants use supercritical boilers which are able to withstand a very high temperature (650-720˚C and pressure (22.1 MPa while producing superheated steam. The thermal efficiency of a supercritical boiler greatly depends on the material of its different components. The supercritical boiler material should possess high creep rupture strength, high thermal conductivity, low thermal expansion, high specific heat and very high temperature withstandability. This paper considers a list of seven supercritical boiler materials whose performance is evaluated based on seven pivotal criteria. Given the intricacy and difficulty of this supercritical boiler material selection problem having interactions and interdependencies between different criteria, this paper applies fuzzy analytic network process to select the most appropriate material for a supercritical boiler. Rene 41 is the best supercritical boiler material, whereas, Haynes 230 is the worst preferred choice.

Putting the five-factor model into context: evidence linking big five traits to narrative identity.

Science.gov (United States)

Raggatt, Peter

2006-10-01

The study examined relationships between the Big Five personality traits and thematic content extracted from self-reports of life history data. One hundred and five "mature age" university students (M=30.1 years) completed the NEO PI-R trait measure, and the Personality Web Protocol. The protocol examines constituents of identity by asking participants to describe 24 key "attachments" from their life histories (significant events, people, places, objects, and possessions). Participants sorted these attachments into clusters and provided a self-descriptive label for each cluster (e.g., "adventurous self"). It was predicted that the thematic content of these cluster labels would be systematically related to Big Five trait scores (e.g., that labels referring to strength or positive emotions would be linked to Extraversion). The hypothesized links were obtained for each of the Big Five trait domains except Conscientiousness. Results are discussed with a view to broadening our understanding of the Five-Factor Model in relation to units of personality other than traits.

Ultra-Supercritical Pressure CFB Boiler Conceptual Design Study

Energy Technology Data Exchange (ETDEWEB)

Zhen Fan; Steve Goidich; Archie Robertson; Song Wu

2006-06-30

Electric utility interest in supercritical pressure steam cycles has revived in the United States after waning in the 1980s. Since supercritical cycles yield higher plant efficiencies than subcritical plants along with a proportional reduction in traditional stack gas pollutants and CO{sub 2} release rates, the interest is to pursue even more advanced steam conditions. The advantages of supercritical (SC) and ultra supercritical (USC) pressure steam conditions have been demonstrated in the high gas temperature, high heat flux environment of large pulverized coal-fired (PC) boilers. Interest in circulating fluidized bed (CFB) combustion, as an alternative to PC combustion, has been steadily increasing. Although CFB boilers as large as 300 MWe are now in operation, they are drum type, subcritical pressure units. With their sizes being much smaller than and their combustion temperatures much lower than those of PC boilers (300 MWe versus 1,000 MWe and 1600 F versus 3500 F), a conceptual design study was conducted herein to investigate the technical feasibility and economics of USC CFB boilers. The conceptual study was conducted at 400 MWe and 800 MWe nominal plant sizes with high sulfur Illinois No. 6 coal used as the fuel. The USC CFB plants had higher heating value efficiencies of 40.6 and 41.3 percent respectively and their CFB boilers, which reflect conventional design practices, can be built without the need for an R&D effort. Assuming construction at a generic Ohio River Valley site with union labor, total plant costs in January 2006 dollars were estimated to be $1,551/kW and $1,244/kW with costs of electricity of $52.21/MWhr and $44.08/MWhr, respectively. Based on the above, this study has shown that large USC CFB boilers are feasible and that they can operate with performance and costs that are competitive with comparable USC PC boilers.

On the design of residential condensing gas boilers

Energy Technology Data Exchange (ETDEWEB)

Naeslund, M.

1997-02-01

Two main topics are dealt with in this thesis. Firstly, the performance of condensing boilers with finned tube heat exchangers and premix burners is evaluated. Secondly, ways of avoiding condensate formation in the flue system are evaluated. In the first investigation, a transient heat transfer approach is used to predict performance of different boiler configurations connected to different heating systems. The smallest efficiency difference between heat loads and heating systems is obtained when the heat exchanger gives a small temperature difference between flue gases and return water, the heat transfer coefficient is low and the thermostat hysteresis is large. Taking into account heat exchanger size, the best boiler is one with higher heat transfer per unit area which only causes a small efficiency loss. The total heating cost at part load, including gas and electricity, has a maximum at the lowest simulated heat load. The heat supplied by the circulation heat pump is responsible for this. The second investigation evaluates methods of drying the flue gases. Reheating the flue gases in different ways and water removal in an adsorbent bed are evaluated. Reheating is tested in two specially designed boilers. The necessary reheating is calculated to approximately 100-150 deg C if an uninsulated masonry chimney is used. The tested boilers show that it is possible to design a proper boiler. The losses, stand-by and convective/radiative, must be kept at a minimum in order to obtain a high efficiency. 86 refs, 70 figs, 16 tabs

Emissions from three wood-fired domestic central heating boilers - heat load dependence

International Nuclear Information System (INIS)

Karlsson, M.L.

1992-01-01

The flue gases from three wood-fired domestic central heating boilers have been characterized. Measurements were made at three part loads; 3, 7 and 15 kW. Two of the boilers were modern multi-fuel boilers, with inverse firing and natural draught. The third boiler was a single-fuel wood boiler, with inverse firing and combustion air supply through a fan. All boilers were environmentally approved; the tar emissions were below 30 mg/MJ at nominal heat load. The following parameters were measured: - CO, CO 2 , NO x , total hydrocarbons (THC), - tar and particulates, - twelve volatile organic compounds (VOC). The limit value for tar emission was heavily exceeded for all three boilers at the part loads at which they were tested. For the two multi-fuel boilers the tar emissions decreased with increasing load level, while the opposite was found for the wood boiler with a fan. The NO x emissions varied between 20 and 120 mg/MJ. The multi-fuel boilers showed increasing NO x emissions with increasing heat load. The single-fuel wood boiler showed NO x emissions at about 60 mg/MJ, independent of load level. The CO and THC levels in general were high. The CO levels varied between 1000 and 2000 mg/MJ. While the THC levels varied between 300 and 4000 mg/MJ. Broadly speaking, the CO and THC levels decreased with increasing load levels for the multi-fuel boilers. For the single-fuel wood boiler the CO and THC levels were roughly the same at all load levels. Out of the twelve VOC compounds which were measured, the following could be detected and quantified. With FTIR analysis: Methane, ethylene, propene and acetylene. With GC analysis: Methanol, phenol and acetic acid. (1 ref., 31 figs., 7 tabs.)

Studies Concerning Water-Surface Deposits in Recovery Boilers

Energy Technology Data Exchange (ETDEWEB)

Strandberg, O; Arvesen, J; Dahl, L

1971-11-15

The Feed-water Committee of the Stiftelsen Svensk Cellulosaforskning (Foundation for Swedish Cellulose Research) has initiated research and investigations which aim to increase knowledge about water-surface deposits in boiler tubes, and the resulting risks of gas-surface corrosion in chemical recovery boilers (sulphate pulp industry). The Committee has arranged with AB Atomenergi, Studsvik, for investigations into the water-surface deposits on tubes from six Scandinavian boilers. These investigations have included direct measurements of the thermal conductivity of the deposits, and determinations of their quantity, thickness and structure have been carried out. Previous investigations have shown that gas-surface corrosion can occur at tube temperatures above 330 deg C. The measured values for the thermal conductivity of the deposits indicate that even with small quantities of deposit (c. 1 g/dm2 ) and a moderate boiler pressure (40 atm), certain types of deposit can give rise to the above-mentioned surface temperature, at which the risk of gas-surface corrosion becomes appreciable. For higher boiler pressures the risk is great even with a minimal layer of deposit. The critical deposit thickness can be as low as 0.1 mm

Energy efficiency in boilers; Eficiencia energetica em caldeiras

Energy Technology Data Exchange (ETDEWEB)

Ponte, Ricardo Silva The [Universidade Federal do Ceara (UFCE), Fortaleza, CE (Brazil). Dept. de Engenharia Eletrica], email: ricthe@dee.ufc.br; Barbosa, Marcos Antonio Pinheiro; Rufino, Maria da Gracas [Universidade de Fortaleza (UNIFOR), CE (Brazil). Dept. de Engenharia Eletrica], emails: marcos_apb@unifor.br, gsrufino@unifor.br

2010-07-01

The boiler is vapor generator equipment that has been widely used in industrial milieu as in electric energy generation in thermoelectric plants. Since their first conception, the boilers have been changed in order to provide security and energetic efficiency. They can present high losses of energy if they don't be operated according to some criteria. A considerable part of boilers operation cost include fuel expenses. So, the adoption of effective steps in order to reduce fuel consumption is important to industry economy, besides it brings environmental benefits through the reduction of pollution liberation. The present article has the objective of emphasizing the effective steps for the economy of energy in boilers, such as, the regulation of combustion; the control of soot and incrustations; the installation of economizers, air heaters and super heaters; the reduction in purges and reintroduction of condensed steam. (author)

Dynamic simulation of a biomass domestic boiler under thermally thick considerations

NARCIS (Netherlands)

Gómez, M. A.; Porteiro, J.; De la Cuesta de Cal, Daniel; Patiño, D.; Míguez, J. L.

2017-01-01

A biomass combustion model with a thermally thick approach is presented and applied to the simulation of a commercial biomass domestic boiler. A subgrid scale model is used to divide the particles into several grid points, each representing one of the different combustion stages. These grid points

Update on the debate about the existence and utility of the Big Five: a ten-year follow-up on Carroll's "the Five-Factor Personality Model: how complete and satisfactory is it?

Science.gov (United States)

Merenda, Peter F

2008-12-01

This paper is a follow-up comment on John B. Carroll's critique of the Big Five Model and his suggestion years ago on how to design and conduct research properly on the structure of personality and its assessment. The status of research on personality factor models is discussed, and conclusions are reached regarding the likely consequences and further prospects of the failure of personality theorists and practitioners to follow through on Carroll's poignant suggestion for required effort.

A review on biomass as a fuel for boilers

Energy Technology Data Exchange (ETDEWEB)

Saidur, R.; Abelaziz, E.A.; Demirbas, A.; Hossain, M.S.; Mekhilef, S. [University of Malaya, Kuala Lumpur (Malaysia). Dept. of Mechanical Engineering

2011-06-15

Currently, fossil fuels such as oil, coal and natural gas represent the prime energy sources in the world. However, it is anticipated that these sources of energy will deplete within the next 40-50 years. Moreover, the expected environmental damages such as the global warming, acid rain and urban smog due to the production of emissions from these sources have tempted the world to try to reduce carbon emissions by 80% and shift towards utilizing a variety of renewable energy resources (RES) which are less environmentally harmful such as solar, wind, biomass etc. in a sustainable way. Biomass is one of the earliest sources of energy with very specific properties. In this review, several aspects which are associated with burning biomass in boilers have been investigated such as composition of biomass, estimating the higher heating value of biomass, comparison between biomass and other fuels, combustion of biomass, co-firing of biomass and coal, impacts of biomass, economic and social analysis of biomass, transportation of biomass, densification of biomass, problems of biomass and future of biomass. It has been found that utilizing biomass in boilers offers many economical, social and environmental benefits such as financial net saving, conservation of fossil fuel resources, job opportunities creation and CO{sub 2} and NO emissions reduction. However, care should be taken to other environmental impacts of biomass such as land and water resources, soil erosion, loss of biodiversity and deforestation. Fouling, marketing, low heating value, storage and collections and handling are all associated problems when burning biomass in boilers. The future of biomass in boilers depends upon the development of the markets for fossil fuels and on policy decisions regarding the biomass market.

Five-Year Wilkinson Microwave Anisotropy Probe Observations: Beam Maps and Window Functions

Science.gov (United States)

Hill, R. S.; Weiland, J. L.; Odegard, N.; Wollack, E.; Hinshaw, G.; Larson, D.; Bennett, C. L.; Halpern, M.; Page, L.; Dunkley, J.; Gold, B.; Jarosik, N.; Kogut, A.; Limon, M.; Nolta, M. R.; Spergel, D. N.; Tucker, G. S.; Wright, E. L.

2009-02-01

Cosmology and other scientific results from the Wilkinson Microwave Anisotropy Probe (WMAP) mission require an accurate knowledge of the beam patterns in flight. While the degree of beam knowledge for the WMAP one-year and three-year results was unprecedented for a CMB experiment, we have significantly improved the beam determination as part of the five-year data release. Physical optics fits are done on both the A and the B sides for the first time. The cutoff scale of the fitted distortions on the primary mirror is reduced by a factor of ~2 from previous analyses. These changes enable an improvement in the hybridization of Jupiter data with beam models, which is optimized with respect to error in the main beam solid angle. An increase in main-beam solid angle of ~1% is found for the V2 and W1-W4 differencing assemblies. Although the five-year results are statistically consistent with previous ones, the errors in the five-year beam transfer functions are reduced by a factor of ~2 as compared to the three-year analysis. We present radiometry of the planet Jupiter as a test of the beam consistency and as a calibration standard; for an individual differencing assembly, errors in the measured disk temperature are ~0.5%. WMAP is the result of a partnership between Princeton University and NASA's Goddard Space Flight Center. Scientific guidance is provided by the WMAP Science Team.

Gas fired boilers and atmospheric pollution

International Nuclear Information System (INIS)

Chiaranello, J.M.

1991-01-01

A general analysis concerning atmospheric pollution is presented: chemical composition and vertical distribution of atmosphere and pollutants, chemical reactions, ozone destruction and production cycles, COx, NOx and SOx pollutions. The gas fired boiler number and repartition in France are presented and the associated pollution is analyzed (CO2, CO, NOx) and quantified. Various pollution control technics concerning gas fired boiler pollutants are described and a pollution criterion for clean gas fired generators is proposed

49 CFR 230.20 - Alteration and repair report for steam locomotive boilers.

Science.gov (United States)

2010-10-01

... boilers. 230.20 Section 230.20 Transportation Other Regulations Relating to Transportation (Continued... boilers. (a) Alterations. When an alteration is made to a steam locomotive boiler, the steam locomotive... maintained for the life of the boiler. (See appendix B of this part.) (b) Welded and riveted repairs to...

DESIGN REPORT: LOW-NOX BURNERS FOR PACKAGE BOILERS

Science.gov (United States)

The report describes a low-NOx burner design, presented for residual-oil-fired industrial boilers and boilers cofiring conventional fuels and nitrated hazardous wastes. The burner offers lower NOx emission levels for these applications than conventional commercial burners. The bu...

Hybrid Intelligent Warning System for Boiler tube Leak Trips

Directory of Open Access Journals (Sweden)

Singh Deshvin

2017-01-01

Full Text Available Repeated boiler tube leak trips in coal fired power plants can increase operating cost significantly. An early detection and diagnosis of boiler trips is essential for continuous safe operations in the plant. In this study two artificial intelligent monitoring systems specialized in boiler tube leak trips have been proposed. The first intelligent warning system (IWS-1 represents the use of pure artificial neural network system whereas the second intelligent warning system (IWS-2 represents merging of genetic algorithms and artificial neural networks as a hybrid intelligent system. The Extreme Learning Machine (ELM methodology was also adopted in IWS-1 and compared with traditional training algorithms. Genetic algorithm (GA was adopted in IWS-2 to optimize the ANN topology and the boiler parameters. An integrated data preparation framework was established for 3 real cases of boiler tube leak trip based on a thermal power plant in Malaysia. Both the IWSs were developed using MATLAB coding for training and validation. The hybrid IWS-2 performed better than IWS-1.The developed system was validated to be able to predict trips before the plant monitoring system. The proposed artificial intelligent system could be adopted as a reliable monitoring system of the thermal power plant boilers.

46 CFR 52.25-7 - Electric boilers (modifies PEB-1 through PEB-19).

Science.gov (United States)

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Electric boilers (modifies PEB-1 through PEB-19). 52.25... ENGINEERING POWER BOILERS Other Boiler Types § 52.25-7 Electric boilers (modifies PEB-1 through PEB-19). Electric boilers required to comply with this part must meet the applicable provisions in this part and the...

46 CFR 97.15-15 - Examination of boilers and machinery.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Examination of boilers and machinery. 97.15-15 Section... VESSELS OPERATIONS Tests, Drills, and Inspections § 97.15-15 Examination of boilers and machinery. It shall be the duty of the chief engineer when assuming charge of the boilers and machinery of a vessel to...

46 CFR 32.35-1 - Boilers and machinery-TB/ALL.

Science.gov (United States)

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Boilers and machinery-TB/ALL. 32.35-1 Section 32.35-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS SPECIAL EQUIPMENT, MACHINERY, AND HULL REQUIREMENTS Main and Auxiliary Machinery § 32.35-1 Boilers and machinery—TB/ALL. Boilers, main and auxiliary...

46 CFR 78.17-30 - Examination of boilers and machinery.

Science.gov (United States)

2010-10-01

... 46 Shipping 3 2010-10-01 2010-10-01 false Examination of boilers and machinery. 78.17-30 Section... OPERATIONS Tests, Drills, and Inspections § 78.17-30 Examination of boilers and machinery. It shall be the duty of the chief engineer when assuming charge of the boilers and machinery of a vessel to examine...

46 CFR 63.25-3 - Electric hot water supply boilers.

Science.gov (United States)

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Electric hot water supply boilers. 63.25-3 Section 63.25... water supply boilers. (a) Electric hot water supply boilers that have a capacity not greater than 454... section except the periodic testing required by paragraph (j) of this section. Electric hot water supply...

Thermodynamic analysis and kinetic modelling of dioxin formation and emissions from power boilers firing salt-laden hog fuel.

Science.gov (United States)

Duo, Wenli; Leclerc, Denys

2007-04-01

Both organic chlorine (e.g. PVC) and inorganic chlorides (e.g. NaCl) can be significant chlorine sources for dioxin and furan (PCDD/F) formation in combustion processes. This paper presents a thermodynamic analysis of high temperature salt chemistry. Its influence on PCDD/F formation in power boilers burning salt-laden wood waste is examined through the relationships between Cl2, HCl, NaCl(g) and NaCl(c). These analyses show that while HCl is a product of combustion of PVC-laden municipal solid waste, NaCl can be converted to HCl in hog fuel boilers by reactions with SO2 or alumino-silicate materials. Cl2 is a strong chlorinating agent for PCDD/F formation. HCl can be oxidized to Cl2 by O2, and Cl2 can be reduced back to HCl by SO2. The presence of sulphur at low concentrations thus enhances PCDD/F formation by increasing HCl concentrations. At high concentrations, sulphur inhibits de novo formation of PCDD/Fs through Cl2 reduction by excess SO2. The effect of NH3, CO and NOx on PCDD/F formation is also discussed. A semi-empirical kinetic model is proposed. This model considers both precursor and de novo formation mechanisms. A simplified version is used as a stack emission model. The kinetic model indicates that stack dioxin emissions will increase linearly with decreasing electrostatic precipitator (ESP) efficiency and exponentially with increasing ESP temperature.

Bubbling fluidized bed boiler for Vanaja power plant

Energy Technology Data Exchange (ETDEWEB)

Sormunen, R.; Haermae, P.; Vessonen, K.; Ketomaeki, A. [ed.

1998-07-01

At the Vanaja Power Plant, on the outskirts of Haemeenlinna, there have been changes which reflect the central goals in IVO`s product development work. At Vanaja, efficiency is combined with environmental friendliness. In the early 1980s, the plant was modernized to produce district heat in addition to electricity. At that time, along with the new gas turbine at the plant, the main fuel, coal, while remaining the fuel for the old boilers, was replaced by natural gas. This year a new type of bubbling fluidized bed boiler enabling continuous use of peat and trial use of biofuels along with coal was introduced at the plant. In addition to the Nordic countries, this kind of technology is required in central eastern Europe, where modernization of ageing power plants is being planned to achieve the best possible solutions in respect of production and the environment. IVO develops a new repair technique for underwater sites

Failure analysis of boiler tubes in lakhra coal power plant

International Nuclear Information System (INIS)

Shah, A.; Baluch, M.M.; Ali, A.

2010-01-01

Present work deals with the failure analysis of a boiler tube in Lakhra fluidized bed combustion power station. Initially, visual inspection technique was adopted to analyse the fractured surface. Detailed microstructural investigations of the busted boiler tube were carried out using light optical microscope and scanning electron microscope. The hardness tests were also performed. A 50 percent decrease in hardness of intact portion of the tube material and from area adjacent to failure was measured, which was found to be in good agreement with the wall thicknesses measured of the busted boiler tube i.e. 4 mm and 2 mm from unaffected portion and ruptured area respectively. It was concluded that the major cause of failure of boiler tube is erosion of material which occurs due the coal particles strike at the surface of the tube material. Since the temperature of boiler is not maintained uniformly. The variations in boiler temperature can also affect the material and could be another reason for the failure of the tube. (author)

PORTER S FIVE FORCES MODEL SCOTT MORTON S FIVE FORCES MODEL BAKOS TREACY MODEL ANALYZES STRATEGIC INFORMATION SYSTEMS MANAGEMENT

Directory of Open Access Journals (Sweden)

Indra Gamayanto

2004-01-01

Full Text Available Wollongong City Council (WCC is one of the most progressive and innovative local government organizations in Australia. Wollongong City Council use Information Technology to gain the competitive advantage and to face a global economy in the future. Porter's Five Force model is one of the models that can be using at Wollongong City Council because porter's five Forces model has strength in relationship between buyer and suppliers (Bargaining power of suppliers and bargaining power of buyers. Other model such as Scott Morton's Five Forces model has strength to analyze the social impact factor, so to gain competitive advantage in the future and have a good IT/IS strategic planning; this model can be use also. Bakos & Treacy model almost the same as Porter's model but Bakos & Treacy model can also be applying into Wollongong City Council to improve the capability in Transforming organization, efficiency, and effectiveness.

Statistical modeling of an integrated boiler for coal fired thermal power plant

Directory of Open Access Journals (Sweden)

Sreepradha Chandrasekharan

2017-06-01

Full Text Available The coal fired thermal power plants plays major role in the power production in the world as they are available in abundance. Many of the existing power plants are based on the subcritical technology which can produce power with the efficiency of around 33%. But the newer plants are built on either supercritical or ultra-supercritical technology whose efficiency can be up to 50%. Main objective of the work is to enhance the efficiency of the existing subcritical power plants to compensate for the increasing demand. For achieving the objective, the statistical modeling of the boiler units such as economizer, drum and the superheater are initially carried out. The effectiveness of the developed models is tested using analysis methods like R2 analysis and ANOVA (Analysis of Variance. The dependability of the process variable (temperature on different manipulated variables is analyzed in the paper. Validations of the model are provided with their error analysis. Response surface methodology (RSM supported by DOE (design of experiments are implemented to optimize the operating parameters. Individual models along with the integrated model are used to study and design the predictive control of the coal-fired thermal power plant. Keywords: Chemical engineering, Applied mathematics

Characteristics of particulate-bound polycyclic aromatic hydrocarbons emitted from industrial grade biomass boilers.

Science.gov (United States)

Yang, Xiaoyang; Geng, Chunmei; Sun, Xuesong; Yang, Wen; Wang, Xinhua; Chen, Jianhua

2016-02-01

Polycyclic aromatic hydrocarbons (PAHs) are carcinogenic or mutagenic and are important toxic pollutants in the flue gas of boilers. Two industrial grade biomass boilers were selected to investigate the characteristics of particulate-bound PAHs: one biomass boiler retro-fitted from an oil boiler (BB1) and one specially designed (BB2) biomass boiler. One coal-fired boiler was also selected for comparison. By using a dilution tunnel system, particulate samples from boilers were collected and 10 PAH species were analyzed by gas chromatography-mass spectrometry (GC-MS). The total emission factors (EFs) of PAHs ranged from 0.0064 to 0.0380 mg/kg, with an average of 0.0225 mg/kg, for the biomass boiler emission samples. The total PAH EFs for the tested coal-fired boiler were 1.8 times lower than the average value of the biomass boilers. The PAH diagnostic ratios for wood pellets and straw pellets were similar. The ratio of indeno(1,2,3-cd)pyrene/[indeno(1,2,3-cd)pyrene+benzo(g,h,i)perylene] for the two biomass boilers was lower than those of the reference data for other burning devices, which can probably be used as an indicator to distinguish the emission of biomass boilers from that of industrial coal-fired boilers and residential stoves. The toxic potential of the emission from wood pellet burning was higher than that from straw pellet burning, however both of them were much lower than residential stove exhausts. Copyright © 2015. Published by Elsevier B.V.

Evaluation of internal boiler components and gases using a high-temperature infrared (IR) lens

Science.gov (United States)

Hammaker, Robert G.; Colsher, Richard J.; Miles, Jonathan J.; Madding, Robert P.

1996-03-01

Fuel accounts for an average of seventy percent of the yearly operational and maintenance costs of all the fossil stations in the United States. This amounts to 30 billion dollars spent for fuel each year. In addition, federal and state environmental codes have been enforcing stricter regulations that demand cleaner environments, such as the reduction of nitrogen oxides (NOx), which are a by-product of the fossil fuel flame. If the burn of the flame inside a boiler could be optimized, the usage of fuel and the amounts of pollution produced would be significantly reduced, and many of the common boiler tube failures can be avoided. This would result in a major dollar savings to the utility industry, and would provide a cleaner environment. Accomplishing these goals will require a major effort from the designers and operators that manufacture, operate, and maintain the fossil stations. Over the past few years re-designed burners have been installed in many boilers to help control the temperatures and shape of the flame for better performance and NOx reduction. However, the measurement of the processes and components inside the furnace, that could assist in determining the desired conditions, can at times be very difficult due to the hostile hot environment. In an attempt to resolve these problems, the EPRI M&D Center and a core group of EPRI member utilities have undertaken a two-year project with various optical manufacturers, IR manufacturers, and IR specialists, to fully develop an optical lens that will withstand the high furnace temperatures. The purpose of the lens is to explore the possibilities of making accurate high temperature measurements of the furnace processes and components in an ever-changing harsh environment. This paper provides an introduction to EPRI's internal boiler investigation using an IR high temperature lens (HTL). The paper describes the objectives, approach, benefits, and project progress.

Visualisation of the velocity field in a scaled water model for validation of numerical calculations for a powder fuelled boiler

Energy Technology Data Exchange (ETDEWEB)

Dumortier, Laurent [Luleaa Univ. of Technology (Sweden)

2001-01-01

Validation of numerical predictions of the flow field in a powder fired industry boiler by flow visualisation in a water model has been studied. The bark powder fired boiler at AssiDomaen Kraftliner in Piteaa has been used as a case study. A literature study covering modelling of combusting flows by water models and different flow visualisation techniques has been carried out. The main conclusion as regards the use of water models is that only qualitative information can be expected. As far as turbulent flow is assured in the model as well as the real furnace, the same Reynolds number is not required. Geometrical similarity is important but modelling of burner jets requires adaptation of the jet diameters in the model. Guidelines for this are available and are presented in the report. The review of visualisation techniques shows that a number of methods have been used successfully for validation of flow field predictions. The conclusion is that the Particle Image Velocimetry and Particle Tracking Velocimetry methods could be very suitable for validation purposes provided that optical access is possible. The numerical predictions include flow fields in a 1130 scale model of the AssiDomaen furnace with water flow as well as flow and temperature fields in the actual furnace. Two burner arrangements were considered both for the model and the actual furnace, namely the present configuration with four front burners and a proposed modification where an additional burner is positioned at a side wall below the other burners. There are many similarities between the predicted flow fields in the model and the full scale furnace but there are also some differences, in particular in the region above the burners and the effects of the low region re-circulation on the lower burner jets. The experiments with the water model have only included the arrangement with four front burners. There were problems determining the velocities in the jets and the comparisons with predictions are

46 CFR 196.15-15 - Examination of boilers and machinery.

Science.gov (United States)

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Examination of boilers and machinery. 196.15-15 Section... VESSELS OPERATIONS Test, Drills, and Inspections § 196.15-15 Examination of boilers and machinery. (a) It shall be the duty of the chief engineer when he assumes charge of the boilers and machinery of a vessel...

Occurrence and prevention of enhanced oxide deposition in boiler flow control orifices

International Nuclear Information System (INIS)

Woolsey, I.S.; Thomas, D.M.; Garbett, K.; Bignold, G.J.

1989-10-01

Once-through boilers, such as those of the AGRs, incorporate flow control orifices at the boiler inlet to ensure a satisfactory flow distribution and stability in the parallel flow paths of the boiler. Deposition of corrosion products in the flow control orifice leads to changes in the orifice pressure loss characteristics, which could lead to problems of flow maldistribution within the boiler, and any adverse consequences resulting from this, such as tube overheating. To date, AGR boiler inlet orifices have not suffered significant fouling due to corrosion products in the boiler feedwater. However, oxide deposition in orifices has been observed in other plants, and in experimental loops operating under conditions very similar to those at inlet to AGR boilers. The lack of deposition in AGR flow control orifices is therefore somewhat surprising. This Report describes studies carried out to examine the factors controlling oxide deposition in flow control orifices, the intention of the work being to explain why deposition has not occurred in AGR boilers to date, and to provide means of preventing deposition in the future should this prove necessary. (author)

Criteria of choosing building structures for rooftop boiler rooms

Directory of Open Access Journals (Sweden)

Plotnikov Artyom

2018-01-01

Full Text Available The paper investigates parameters of noise and vibration distribution in the territory of residential area depending on the structural materials and power of independent heat supply systems. Rooftop boiler rooms are decentralized heat supply systems in buildings. Today, residential areas are strongly affected by noise and vibrations. Adverse effects are isolated by buildings materials, protective shields and floating floors. Rooftop boiler rooms located in Tyumen city were investigated within this research. Structures of rooftop boiler rooms were analyzed. Acoustic analysis results and the parameters of equivalent continuous sound level are presented. An option for improvement of rooftop boiler rooms structures is suggested. Comparison of capital investments in construction and installation activities is carried out. Conclusion on capital investments required for noise protection is made.