WorldWideScience

Sample records for boiler tubes

  1. Modeling of fire-tube boilers

    OpenAIRE

    Ortiz, F.J. Gutiérrez

    2011-01-01

    Abstract In fire-tube boilers, the flue gas passes inside boiler tubes, and heat is transferred to water on the shell side. A dynamic model has been developed for the analysis of boiler performance, and Matlab has been applied for integrating it. The mathematical model developed is based on the first principles of mass, energy and momentum conservations. In the model, the two parts of the boiler (fire/gas and water/steam sides), the economizer, the superheater and the heat recovery...

  2. 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.

  3. Removal of External Deposits on Boiler Tubes

    Directory of Open Access Journals (Sweden)

    C. P. De

    1970-07-01

    Full Text Available The superheater tubes in Port and Starboard boilers were found to have completely clogged by heavy deposits, which on analysis mainly vanadium pentoxide and sodium sulphmatter. The cleaning of the deposits was accomplished by alternate spraying with 15-20 per cent hydrogen peroxide and washing with hot water jets. Over the past two years, since the date of cleaning, the IN ship is operating without any trouble in the boilers.

  4. CFD modeling of a boiler's tubes rupture

    International Nuclear Information System (INIS)

    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

  5. 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.

  6. Computer simulation of the fire-tube boiler hydrodynamics

    OpenAIRE

    Khaustov Sergei A.; Zavorin Alexander S.; Buvakov Konstantin V.; Sheikin Vyacheslav A.

    2015-01-01

    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.

  7. CFD Studies on Multi Lead Rifled [MLR] Boiler Tubes

    OpenAIRE

    Dr T C Mohankumar

    2013-01-01

    This paper reports the merits of multi lead rifled [MLR] tubes in vertical water tube boiler using CFD tool. Heat transfer enhancement of MLR tubes was mainly taken in to consideration. Performance of multi lead rifled tube was studied by varying its influencing geometrical parameter like number of rifling, height of rifling, length of pitch of rifling for a particular length. The heat transfer analysis was done at operating conditions of an actual coal fired water tube boiler situated at Apo...

  8. Maintenance of immersion ultrasonic testing on the water tube boiler

    International Nuclear Information System (INIS)

    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)

  9. 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....

  10. CFD Studies on Multi Lead Rifled [MLR] Boiler Tubes

    Directory of Open Access Journals (Sweden)

    Dr T C Mohankumar

    2013-09-01

    Full Text Available This paper reports the merits of multi lead rifled [MLR] tubes in vertical water tube boiler using CFD tool. Heat transfer enhancement of MLR tubes was mainly taken in to consideration. Performance of multi lead rifled tube was studied by varying its influencing geometrical parameter like number of rifling, height of rifling, length of pitch of rifling for a particular length. The heat transfer analysis was done at operating conditions of an actual coal fired water tube boiler situated at Apollo Tyres LTD, Chalakudy, India for saturated process steam production. The results showed that the heat transfer increased when compared with existing inner plane wall water tubes.

  11. Development of the boiler tube wall thickness ultrasonic detector

    International Nuclear Information System (INIS)

    Wall thickness of fossil fuel firing power boiler tubes are measured by ultrasonic test at regular intervals as part of in-service inspections. The measuring tubes are located high up on the boiler and at restricted sites, and many man-hours are required for preparatory of boiler tube wall thickness scale removal. To improve the efficiency and reliability of boiler tube wall thickness measurements, a system was developed for measuring the tube wall thickness by ultrasonic test from inside the tube. The primary features of this system are: 1) polishing on the outersurface of boiler tubes is not necessary because measurements are made from inside. (Reduction of man-hours), 2) measurements in limited places where manual measurement is difficult or impossible is made possible because automatic measurement from inside the tube is made by an ultrasonic probe introduced into the tube from the inspection hole of the header. (Improvement of reliability), and 3) the tube wall thickness is measured by a submerged ultrasonic rotary probe at an accuracy of ±0.1 mm along the full length. (Improvement of reliability)

  12. Failure analysis of boiler tubes in lakhra coal power plant

    International Nuclear Information System (INIS)

    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)

  13. Failure of marine boiler tube: A case history

    Directory of Open Access Journals (Sweden)

    V. A. Dere

    1963-01-01

    Full Text Available An interesting case of marine boiler tube failure is described. As a result of local overheating, a ballooning burst occurred in a boiler tube. Evidence showed that a temperature of over 1600/degree/F (87/degree/C had been reached before rupture. The presence of a thin film of copper arising from the auxiliary equipments of the boiler, caused pittings in the metal. failure was thus attributed to local overheating accelerated by an inner deposit of heat insulating scale.

  14. Boiler tube corrosion characterization with a scanning thermal line

    Science.gov (United States)

    Cramer, K. Elliott; Jacobstein, A. Ronald; Reilly, Thomas L.

    2001-03-01

    Wall thinning due to corrosion in utility boiler waterwall tubing is a significant operational concern for boiler operators. Historically, conventional ultrasonics has been used for inspection of these tubes. Unfortunately, ultrasonic inspection is very manpower intense and slow. Therefore, thickness measurements are typically taken over a relatively small percentage of the total boiler wall and statistical analysis is used to determine the overall condition of the boiler tubing. Other inspection techniques, such as electromagnetic acoustic transducer (EMAT), have recently been evaluated, however they provide only a qualitative evaluation - identifying areas or spots where corrosion has significantly reduced the wall thickness. NASA Langley Research Center, in cooperation with ThermTech Services, has developed a thermal NDE technique designed to quantitatively measure the wall thickness and thus determine the amount of material thinning present in steel boiler tubing. The technique involves the movement of a thermal line source across the outer surface of the tubing followed by an infrared imager at a fixed distance behind the line source. Quantitative images of the material loss due to corrosion are reconstructed from measurements of the induced surface temperature variations. This paper will present a discussion of the development of the thermal imaging system as well as the techniques used to reconstruct images of flaws. The application of the thermal line source coupled with the analysis technique represents a significant improvement in the inspection speed and accuracy for large structures such as boiler waterwalls.

  15. Modelling and simulating fire tube boiler performance

    DEFF Research Database (Denmark)

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

    2003-01-01

    A model for a flue gas boiler covering the flue gas and the water-/steam side has been formulated. The model has been formulated as a number of sub models that are merged into an overall model for the complete boiler. Sub models have been defined for the furnace, the convection zone (split in 2: a...... zone submerged in water and a zone covered by steam), a model for the material in the boiler (the steel) and 2 models for resp. the water/steam zone (the boiling) and the steam. The dynamic model has been developed as a number of Differential-Algebraic-Equation system (DAE). Subsequently Mat......Lab/Simulink has been applied for carrying out the simulations. To be able to verify the simulated results experiments has been carried out on a full scale boiler plant....

  16. Modelling and simulating fire tube boiler performance

    DEFF Research Database (Denmark)

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

    2003-01-01

    A model for a ue gas boiler covering the ue gas and the water-/steam side has been formulated. The model has been formulated as a number of sub models that are merged into an overall model for the complete boiler. Sub models have been dened for the furnace, the convection zone (split in 2: a zone...... submerged in water and a zone covered by steam), a model for the material in the boiler (the steel) and 2 models for resp. the water/steam zone (the boiling) and the steam. The dynamic model has been developed as a number of Differential-Algebraic- Equation system (DAE). Subsequently MatLab/Simulink has...... been applied for carrying out the simulations. To be able to verify the simulated results an experiments has been carried out on a full scale boiler plant....

  17. Simulasi Thermal Stress Pada Tube Superheater Package Boiler

    OpenAIRE

    Hamdani

    2013-01-01

    This project investigates the thermal stress behavior and the mechanisms of superheater tube failure with experimental method and numerical analysis. First of all the procedures for failure analysis were applied to determine the root cause of them. A visual assessment of boiler critical pressure parts was carried out, and then the failed tube is examined by nondestructive evaluation. For the numerical domain, initially the elastic solution for a superheater tube subjected to an internal press...

  18. Modelling of a one pass smoke tube boiler

    DEFF Research Database (Denmark)

    Karstensen, Claus M. S.; Sørensen, Kim

    2004-01-01

    A nonlinear state-space model with five states describing a one pass smoke tube boiler has been formulated. By means of mass- and energy-balance the model describes the dynamics of the Furnace, the Convection Zone and the Water/Steam Part and the three sub models are merged into an overall model....

  19. Influence of furnace tube shapeon thermal strain of fire-tube boilers

    Directory of Open Access Journals (Sweden)

    Gaćeša Branka

    2014-01-01

    Full Text Available The aim of this paper is to use numerical analysis and fine element method-FEM to investigate the influence of furnace tube shape on the thermal strain of fire-tube boilers. Thermal stresses in corrugated furnace tubes of different shape, i.e. with different corrugation pitch and depth, were analysed first. It was demonstrated that the thermal stresses in corrugated furnace tube are significantly reduced with the increase of corrugation depth. Than deformations and stresses in the structure of a fire-tube boiler were analysed in a real operating condition, for the cases of installed plain furnace tube and corrugated furnace tubes with different shapes. It was concluded that in this fire-tube boiler, which is of larger steam capacity, the corrugated furnace tube must be installed, as well as that the maximal stress in the construction is reduced by the installation of the furnace tube with greater corrugation depth. The analysis of stresses due to pressure and thermal loads pointed out that thermal stresses are not lower-order stresses in comparison to stresses due to pressure loads, so they must be taken into consideration for boiler strength analysis. [Projekat Ministarstva nauke Republike Srbije, br. TR 35040 i br. TR 35011

  20. Metallurgical Analysis of Cracks Formed on Coal Fired Boiler Tube

    Science.gov (United States)

    Kishor, Rajat; Kyada, Tushal; Goyal, Rajesh K.; Kathayat, T. S.

    2015-02-01

    Metallurgical failure analysis was carried out for cracks observed on the outer surface of a boiler tube made of ASME SA 210 GR A1 grade steel. The cracks on the surface of the tube were observed after 6 months from the installation in service. A careful visual inspection, chemical analysis, hardness measurement, detailed microstructural analysis using optical and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy were carried out to ascertain the cause for failure. Visual inspection of the failed tube revealed the presence of oxide scales and ash deposits on the surface of the tube exposed to fire. Many cracks extending longitudinally were observed on the surface of the tube. Bulging of the tube was also observed. The results of chemical analysis, hardness values and optical micrographs did not exhibit any abnormality at the region of failure. However, detailed SEM with EDS analysis confirmed the presence of various oxide scales. These scales initiated corrosion at both the inner and outer surfaces of the tube. In addition, excessive hoop stress also developed at the region of failure. It is concluded that the failure of the boiler tube took place owing to the combined effect of the corrosion caused by the oxide scales as well as the excessive hoop stress.

  1. Thermal Behavior of Floor Tubes in a Kraft Recovery Boiler

    Energy Technology Data Exchange (ETDEWEB)

    Barker, R.E.; Choudhury, K.A.; Gorog, J.P.; Hall, L.M.; Keiser, J.R.; Sarma, G.B.

    1999-09-12

    The temperatures of floor tubes in a slope-floored black liquor recovery boiler were measured using an array of thermocouples located on the tube crowns. It was found that sudden, short duration temperature increases occurred with a frequency that increased with distance from the spout wall. To determine if the temperature pulses were associated with material falling from the convective section of the boiler, the pattern of sootblower operation was recorded and compared with the pattern of temperature pulses. During the period from September, 1998, through February, 1999, it was found that more than 2/3 of the temperature pulses occurred during the time when one of the fast eight sootblowers, which are directed at the back of the screen tubes and the leading edge of the first superheater bank, was operating.

  2. Corrosion of evaporator tubes in low emission steam boilers

    OpenAIRE

    S. Topolska; J. Łabanowski

    2010-01-01

    Purpose: of this paper is to reveal the mechanisms of corrosion processes of outer surfaces of low-emission steam boiler evaporator tubes. Examinations were performed to find the reasons of different corrosion susceptibility of tubes situated at combustion chamber on various levels.Design/methodology/approach: Examinations were conducted on several segments of Ø 57 x 5.0 mm evaporator tubes made of 16M (16Mo3) steel grade. Segments were taken from level of 10 meters and 18 meters from the cha...

  3. Corrosion of evaporator tubes in low emission steam boilers

    Directory of Open Access Journals (Sweden)

    S. Topolska

    2010-04-01

    Full Text Available Purpose: of this paper is to reveal the mechanisms of corrosion processes of outer surfaces of low-emission steam boiler evaporator tubes. Examinations were performed to find the reasons of different corrosion susceptibility of tubes situated at combustion chamber on various levels.Design/methodology/approach: Examinations were conducted on several segments of Ø 57 x 5.0 mm evaporator tubes made of 16M (16Mo3 steel grade. Segments were taken from level of 10 meters and 18 meters from the chamber bottom of low-emission coal fired steam boiler after two years operation. Microstructure degradation of base material was estimated. Metallographic evaluation of scale morphology, its micro sites chemical composition analysis and distribution of elements on cross sections have been performed.Findings: Eexaminations of evaporator tubes indicated that reduction of wall thickness was considerable at the segments taken from level of 10 m, when at level of 18 m this reduction was small. The morphology of scales consisted of external layer which was porous and weakly connected to the tube surface, and internal layer, which was dense and adherent to the base metal. In these two layers the bands reach in sulfur were detected. The sulfide corrosion seems to be the main degradation mechanism of the tube surface at the level of 10 m.Research limitations/implications: Corrosion of the water wall tubes in low-emission steam boilers is a result of reaction of steel tube surface with the aggressive substoichiometric environment contains sulfur. The chemical composition of flue gases changes along the water wall. The exact compound of flue gases has not been determined in this study.Practical implications: Prevention of water wall tubes corrosion can be achieved by changing in operation conditions or replacement of tube materials. The first mentioned action is limited to accurate burner’s adjustment or introduces a flow of additional air along the walls and create

  4. A risk approach to the management of boiler tube thinning

    International Nuclear Information System (INIS)

    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

  5. Fracture in a steam boiler generator tube

    International Nuclear Information System (INIS)

    This study briefly describes the abrupt rupture of a classical heater tube in 15D3 steel (steel rarely used in France). This breakage had occurred after 10 years of service. The authors conclude in a local overheating having provoked an intergranular precipitation, itself triggering a breakage. (Author). 4 refs., 5 figs., 2 tabs

  6. Development of automatic inspection robot for boiler tubes using EMAT

    International Nuclear Information System (INIS)

    In this study, a mobile robotic system using NDT (Non-destructive testing) method is developed for automatic diagnosis of the boiler tubes. The developed mobile robot crawls the surface of the tubes and detects in-pipe defects such as pinholes, cracks and thickness reduction by corrosion and/or erosion using EMAT (Electro-magnetic Acoustic Transducer) sensors. Automation of fault detection by means of mobile robotic systems for large-scale structures helps to prevent significant troubles without danger of human beings under harmful environment. In this study a preliminary result with guided wave inspection for defect detection is shown.

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

    OpenAIRE

    Al-Kayiem Hussain H.; Al-Naimi Firas B. I.; Amat Wan N. Bt Wan

    2014-01-01

    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 i...

  8. 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.

  9. Hydrogen attack evaluation of boiler tube using ultrasonic wave

    International Nuclear Information System (INIS)

    The presence of hydrogen in industrial plants is a source of damage. Hydrogen attack is one such form of degradation and often causing large tube ruptures that necessitate an immediate shutdown. Hydrogen attack may reduce the fracture toughness as well as the strength of steels. This reduction is caused partially by the presence of cavities and microcracks at the grain boundaries. In the past several techniques have been used with limited results. This paper describes the application of an ultrasonic velocity, attenuation and backscatter techniques for detecting the presence of hydrogen damage in utility boiler tubes. Ultrasonic tests showed a decrease in wave velocity and an increase in attenuation. Such results demonstrate the potential for ultrasonic nondestructive testing to quantify damage. Based on this study, recommendations are that both velocity and attenuation be used to detect hydrogen attack in steels.

  10. 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.

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

    OpenAIRE

    Khaustov Sergei; Belousova Yana

    2015-01-01

    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 ...

  12. Composite tube cracking in kraft recovery boilers: A state-of-the-art review

    Energy Technology Data Exchange (ETDEWEB)

    Singbeil, D.L.; Prescott, R. [Pulp and Paper Research Inst. of Canada, Vancouver, British Columbia (Canada); Keiser, J.R.; Swindeman, R.W. [Oak Ridge National Lab., TN (United States)

    1997-07-01

    Beginning in the mid-1960s, increasing energy costs in Finland and Sweden made energy recovery more critical to the cost-effective operation of a kraft pulp mill. Boiler designers responded to this need by raising the steam operating pressure, but almost immediately the wall tubes in these new boilers began to corrode rapidly. Test panels installed in the walls of the most severely corroding boiler identified austenitic stainless steel as sufficiently resistant to the new corrosive conditions, and discussions with Sandvik AB, a Swedish tube manufacturer, led to the suggestion that coextruded tubes be used for water wall service in kraft recovery boilers. Replacement of carbon steel by coextruded tubes has solved most of the corrosion problems experienced by carbon steel wall tubes, however, these tubes have not been problem-free. Beginning in early 1995, a multidisciplinary research program funded by the US Department of Energy was established to investigate the cause of cracking in coextruded tubes and to develop improved materials for use in water walls and floors of kraft recovery boilers. One portion of that program, a state-of-the-art review of public- and private-domain documents related to coextruded tube cracking in kraft recovery boilers is reported here. Sources of information that were consulted for this review include the following: tube manufacturers, boiler manufacturers, public-domain literature, companies operating kraft recovery boilers, consultants and failure analysis laboratories, and failure analyses conducted specifically for this project. Much of the information contained in this report involves cracking problems experienced in recovery boiler floors and those aspects of spout and air-port-opening cracking not readily attributable to thermal fatigue. 61 refs.

  13. The use of laser-induced plasma spectroscopy technique for the characterization of boiler tubes

    International Nuclear Information System (INIS)

    The present work focuses on the characterization of boiler tube walls using laser-induced plasma spectroscopy technique with visual inspection by optical and scanning electron microscopy of the cross-sections of these tubes. In a watertube boiler, water runs through tubes that are surrounded by a heating source. As a result, the water is heated to very high temperatures, causing accumulation of deposits on the inside surfaces of the tubes. These deposits play an important role in the efficiency of the boiler tube because they produce a reduction of the boiler heat rate and an increase in the number of tube failures. The objectives are to determine the thickness and arrangement of deposits located on the highest heat area of the boiler and compare them with tube parts where the heat flux is lower. The major deposits found were copper and magnetite. These deposits come mainly from the boiler feedwater and from the reaction between iron and water, and they do not form on the tube walls at a uniform rate over time. Their amount depends on the areas where they are collected. A Nd:YAG laser operating at 355 nm has been used to perform laser-induced plasma spectra and depth profiles of the deposits

  14. On-Line Life Monitoring Technique for Tube Bundles of Boiler High-Temperature Heating Surface

    Institute of Scientific and Technical Information of China (English)

    Yang Dong; Wang Zhongyuan

    2005-01-01

    High-temperature heating surface such as superheater and reheater of large-sized utility boiler all experiences a relatively severe working conditions. The failure of boiler tubes will directly impact the safe and economic operation of boiler. An on-line life monitoring model of high-temperature heating surface was set up according to the well-known L-M formula of the creep damages. The tube wall metal temperature and working stress was measured by on-line monitoring, and with this model, the real-time calculation of the life expenditure of the heating surface tube bundles were realized. Based on the technique the on-line life monitoring and management system of high-temperature heating surface was developed for a 300 MW utility boiler. An effective device was thus suggested for the implementation of the safe operation and the condition-based maintenance of utility boilers.

  15. Formation of corrosion products protecting surfaces of the boiler proper tubes from the combustion chamber

    OpenAIRE

    Pietrzyk, M.; S. Król

    2007-01-01

    Purpose: The aim of this paper is to determine how the oxidation product layer of the steel applied for the radiant tubes should increase if we are going to obtain the lowest possible corrosion losses.Design/methodology/approach: Boiler tubes, made of 13CrMo4-5 steel were subjected to tests. In the boiler BP-1150, the tubes ø 30 x 5 mm are joined by fins and form a membrane shield. According to the maps of tube wall thickness, in the zone of the highest heat load, sectors of the shield were s...

  16. 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)

    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 134I was shown only by Boiler - 5. No other boilers showed any activity of 134I. 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)

  17. Mechanical Design of Steel Tubing for Use in Black Liquor Recovery Boilers

    Energy Technology Data Exchange (ETDEWEB)

    Taljat, B.; Zacharaia, T.; Wang, X.; Kesier, J.; Swindeman, R.; Hubbard, C.

    1999-05-26

    Finite element models were developed for thermal-mechanical analysis of black liquor recovery boiler floor tubes. Residual stresses in boiler floors due to various manufacturing processes were analyzed. The modeling results were verified by X-ray and neutron diffraction measurements at room temperature on as-manufactured tubes as well as tubes after service. The established finite element models were then used to evaluate stress conditions during boiler operation. Using these finite element models, a parametric response surface study was performed to investigate the influence of material properties of the clad layer on stresses in the floor tubes during various boiler operating conditions, which yielded a generalized solution of stresses in the composite tube floors. The results of the study are useful for identifying the mechanisms of cracking experienced by recovery boilers. Based on the results of the response surface study, a recommendation was made for more suitable materials in terms of the analyzed mechanical properties. Alternative materials and manufacturing processes are being considered to improve the resistance to cracking and the in-service life of composite tubes. To avoid numerous FE stress-strain analyses of composite tubes made of different material combinations, a response surface study was performed that considered two essential mechanical properties of the clad material - coefficient of thermal expansion and yield stress - as independent variables. The response surface study provided a generalized solution of stresses in the floor in terms of the two selected parameters.

  18. Leak detection evaluation of boiler tube for power plant using acoustic emission

    International Nuclear Information System (INIS)

    Main equipment of thermal power plant, such as boiler and turbine, are designed and manufactured by domestic techniques. And also the automatic control facilities controlling the main equipment are at the applying step of the localization. and many parts of BOP(Balance Of Plant) equipment are utilizing, localized. But because the special equipment monitoring the operation status of the main facilities such as boiler and turbine are still dependent upon foreign technology and especially boiler tube leak detection system is under the initial step of first application to newly-constructed plants and the manufacturing and application are done by foreign techniques mostly, fast localization development is required. Therefore, so as to study and develop boiler tube leak detection system, we performed studying on manufacturing, installation in site, acoustic emission(AE) signal analysis and discrimination etc. As a result of studying on boiler tube leak detection using AE, we conformed that diagnosis for boiler tube and computerized their trend management is possible, and also it is expected to contribute to safe operation of power generation facilities.

  19. Investigation and analysis of short overheat in boiler tube failure in power plant units

    International Nuclear Information System (INIS)

    Boiler tube failure are the main cause of forced outages of power generating units and due to cost, Penalty is very high. Sources and reasons of tube failures are various, but it can be generally categorized by mechanical and corrosion factors with 81% and 19% contributions, respectively. Among the mechanical factors short overheat has the major contribution in water wall and superheater tube, failure. In this paper short overheat mechanism (with appearance and metallurgical features) and its prevention method is over viewed

  20. 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.

  1. Investigation into Cause of High Temperature Failure of Boiler Superheater Tube

    Science.gov (United States)

    Ghosh, D.; Ray, S.; Roy, H.; Shukla, A. K.

    2015-04-01

    The failure of the boiler tubes occur due to various reasons like creep, fatigue, corrosion and erosion. This paper highlights a case study of typical premature failure of a final superheater tube of 210 MW thermal power plant boiler. Visual examination, dimensional measurement, chemical analysis, oxide scale thickness measurement, microstructural examination are conducted as part of the investigations. Apart from these investigations, sulfur print, Energy Dispersive spectroscopy (EDS) and X ray diffraction analysis (XRD) are also conducted to ascertain the probable cause of failure of final super heater tube. Finally it has been concluded that the premature failure of the super heater tube can be attributed to the combination of localized high tube metal temperature and loss of metal from the outer surface due to high temperature corrosion. The corrective actions have also been suggested to avoid this type of failure in near future.

  2. Estimation of residual life of boiler tubes using steamside oxide scale thickness

    International Nuclear Information System (INIS)

    In thermal power plants, remaining-life-estimation of boiler tubes is required at regular intervals for a safer and a better functionality of boilers. In this paper, a new method is proposed for the residual life estimation of service exposed boiler tubes using Non-Destructive Ultrasonic Oxide scale thickness measurements, average metal temperature and creep master curve. While steady state conduction heat transfer equations are solved to calculate the average metal temperature, creep master curve is generated from short term stress rupture data of rupture life less than 5000 h on a virgin material. In the present study, the residual life of T22 (2.25Cr-1Mo) service exposed Platen Superheater tube is estimated using two master creep curves, i.e. Larson-Miller Parametric (LMP) method of standard ASME T22 creep data and Wilshire approach of short term stress rupture data of T22. As the residual life is calculated from fundamental conduction heat transfer theory and creep rupture data, the proposed method can be applied for different grades of boiler materials. -- Highlights: ► Residual life is calculated from non-destructive oxide scale thickness, creep master curve and average metal temperature. ► A new method is proposed for calculating residual life using above parameters and from conduction heat transfer principles. ► The method can be applied to different boiler grades for estimating residual life and hence the method is generic

  3. Heat transfer characteristics of 2t/h class modular water tube type boiler

    International Nuclear Information System (INIS)

    A finned tube type evaporator module has been proposed for a 2t/h class water tube type industrial boiler with multiple burners. The geometry of the fins was changed at each module to equalize the evaporation. The modules were designed by considering the energy balance at each row rather than by following a conventional bulk design procedure. The designed module was built into a 2t/h class water tube type boiler, and its performance was tested. A numerical simulation was also conducted to evaluate the two or three dimensional effects of factors such as the inlet conditions. The numerical simulation also included the conjugate heat transfer problem to predict the fin tip temperature. The heat transfer coefficient with fins is lower than that obtained from the empirical correlation of a bare tube. The fin tip temperature from CFD is higher than that from the analytical solution

  4. Heat transfer characteristics of 2t/h class modular water tube type boiler

    Energy Technology Data Exchange (ETDEWEB)

    Ahn, Joon [Kookmin Univ., Seoul (Korea, Republic of); Hwang, Sang Soon [Univ. of Incheon, Incheon (Korea, Republic of)

    2012-11-15

    A finned tube type evaporator module has been proposed for a 2t/h class water tube type industrial boiler with multiple burners. The geometry of the fins was changed at each module to equalize the evaporation. The modules were designed by considering the energy balance at each row rather than by following a conventional bulk design procedure. The designed module was built into a 2t/h class water tube type boiler, and its performance was tested. A numerical simulation was also conducted to evaluate the two or three dimensional effects of factors such as the inlet conditions. The numerical simulation also included the conjugate heat transfer problem to predict the fin tip temperature. The heat transfer coefficient with fins is lower than that obtained from the empirical correlation of a bare tube. The fin tip temperature from CFD is higher than that from the analytical solution.

  5. Dynamic instabilities in radiation-heated boiler tubes for solar central receivers

    Science.gov (United States)

    Wolf, S.; Chan, K. C.; Chen, K.; Yadigaroglu, G.

    1982-11-01

    Density-wave instabilities have been investigated in circumferentially nonuniform radiation-heated boiler tubes, simulating solar heating. Analysis and experimental data are presented. The analysis provides the basis for a computer code, STEAMFREQ-I, for the prediction of density-wave instabilities in boiler tubes with imposed heat flux. The key model features include a drift-flux flow model in the boiling region, spatial variation of heat flux, wall dynamics, and variable steam properties in the superheat region. The experimental data include results from two radiation heated boiler panel tests. The data are applicable to central receivers for solar electric power plants. Data for stable and unstable conditions are compared with predictions from STEAMFREQ-I.

  6. Parameter Tuning via Genetic Algorithm of Fuzzy Controller for Fire Tube Boiler

    Directory of Open Access Journals (Sweden)

    Osama I. Hassanein

    2012-04-01

    Full Text Available The optimal use of fuel energy and water in a fire tube boiler is important in achieving economical system operation, precise control system design required to achieve high speed of response with no overshot. Two artificial intelligence techniques, fuzzy control (FLC and genetic-fuzzy control (GFLC applied to control both of the water/steam temperature and water level control loops of boiler. The parameters of the FLC are optimized to locating the optimal solutions to meet the required performance objectives using a genetic algorithm. The parameters subject to optimization are the width of the membership functions and scaling factors. The performance of the fire tube boiler that fitted with GFLC has reliable dynamic performance as compared with the system fitted with FLC.

  7. Stress and integrity analysis of steam superheater tubes of a high pressure boiler

    OpenAIRE

    Daniel Leite Cypriano Neves; Jansen Renato de Carvalho Seixas; Ediberto Bastos Tinoco; Adriana da Cunha Rocha; Ibrahim de Cerqueira Abud

    2004-01-01

    Sources that can lead to deterioration of steam superheater tubes of a high pressure boiler were studied by a stress analysis, focused on internal pressure and temperature experienced by the material at real operating conditions. Loss of flame control, internal deposits and unexpected peak charge are factors that generate loads above the design limit of tube materials, which can be subjected to strain, buckling, cracks and finally rupture in service. To evaluate integrity and dependability of...

  8. Aspects of high temperature corrosion of boiler tubes

    Energy Technology Data Exchange (ETDEWEB)

    Spiegel, M.; Bendick, W. [Salzgitter-Mannesmann-Forschung GmbH, Duisburg (Germany)

    2008-07-01

    The development of new boiler steels for power generation has to consider significant creep strength as well as oxidation and corrosion resistance. High temperature corrosion of boiler materials concerns steam oxidation as well as fireside corrosion of parts, in contact with the flue gas. It will be shown that depending on the quality of the fuel, especially chlorine and sulphur are responsible for most of the fireside corrosion problems. Corrosion mechanisms will be presented for flue gas induced corrosion (HCl) and deposit induced corrosion (chlorides and sulfates). Especially for the 700 C technology, deposit induced corrosion issues have to be considered and the mechanisms of corrosion by molten sulfates 'Hot Corrosion' will be explained. Finally, an overview will be given on the selection of suitable materials in order to minimise corrosion relates failures. (orig.)

  9. Overheating failure of superheater suspension tubes of a captive thermal power plant boiler

    International Nuclear Information System (INIS)

    Failure of boiler tubes is the foremost cause of forced boiler outages. One of the predominant failure mechanism of boiler tubes is the stress rupture failure in the form of either short term overheating or long term overheating which are normally encountered in superheater and reheater sections working in the creep range. The strength of the boiler tube depends on the stress level as well on the temperature of exposure in the creep range. An increase in either can reduce the time to rupture. Time at the exposure temperature is an important factor based on which the failures are categorised as either short term or long term. Though there is no established time duration criteria demarcating the short or long term stress rupture failures, depending on the various manifestations on the failed samples, one can categorise the failure. This paper addresses one such stress rupture failure in the superheater section of a captive thermal power plant of a refinery. Multiple failures on the suspension coil of a superheater section was investigated for the cause of failure. Laboratory investigation of the failed sample involved visual inspection, dimensional measurements, chemical analysis of internal deposits and microstructural study. On the basis of these, the failure was attributed to deposition of trisodium phosphate carried over by the feed water into the superheater section resulting in chokage and increase in local operating hoop stresses of the tube. The ultimate failure was thus categorised as long term overheating failure. (author)

  10. Thermal Nondestructive Characterization of Corrosion in Boiler Tubes by Application fo a Moving Line Heat Source

    Science.gov (United States)

    Cramer, K. Elliott; Winfree, William P.

    2000-01-01

    Wall thinning in utility boiler waterwall tubing is a significant inspection concern for boiler operators. Historically, conventional ultrasonics has been used lor inspection of these tubes. This technique has proved to be very labor intensive and slow. This has resulted in a "spot check" approach to inspections, making thickness measurements over a relatively small percentage of the total boiler wall area. NASA Langley Research Center has developed a thermal NDE technique designed to image and quantitatively characterize the amount of material thinning present in steel tubing. The technique involves the movement of a thermal line source across the outer surface of the tubing followed by an infrared imager at a fixed distance behind the line source. Quantitative images of the material loss due to corrosion are reconstructed from measurements of the induced surface temperature variations. This paper will present a discussion of the development of the thermal imaging system as well as the techniques used to reconstruct images of flaws. The application of the thermal line source, coupled with this analysis technique, represents a significant improvement in the inspection speed for large structures such as boiler waterwalls while still providing high-resolution thickness measurements. A theoretical basis for the technique will be presented thus demonstrating the quantitative nature of the technique. Further, results of laboratory experiments on flat Panel specimens with fabricated material loss regions will be presented.

  11. Nickel-chromium plasma spray coatings: A way to enhance degradation resistance of boiler tube steels in boiler environment

    Science.gov (United States)

    Sidhu, Buta Singh; Prakash, S.

    2006-03-01

    Boiler tube steels, namely low carbon steel ASTM-SA-210-Grades A1 (GrA1), 1Cr-0.5Mo steel ASTM-SA213-T-11 (T11), and 2.25Cr-1 Mo steel ASTM-SA213-T-22(T22), were used as substrate steels. Ni-22Cr-10Al-1Y powder was sprayed as a bond coat 150 μm thick before a 200 μm final coating of Ni-20Cr was applied Coatings were characterized prior to testing in the environment of a coal fire boiler. The uncoated and coated steels were inserted in the platen superheater zone of a coal fired boiler at around 755°C for 10 cycles, each 100 h. Coated steels showed lower degradation (erosion-corrosion) rate than uncoated steels showed. The lowest rate was observed in the case of Ni-20Cr coated T11 steel. Among the uncoated steels, the observed rate of degradation was the lowest for the T22 steel.

  12. 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.

  13. 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.

  14. Formation of corrosion products protecting surfaces of the boiler proper tubes from the combustion chamber

    Directory of Open Access Journals (Sweden)

    M. Pietrzyk

    2007-04-01

    Full Text Available Purpose: The aim of this paper is to determine how the oxidation product layer of the steel applied for the radiant tubes should increase if we are going to obtain the lowest possible corrosion losses.Design/methodology/approach: Boiler tubes, made of 13CrMo4-5 steel were subjected to tests. In the boiler BP-1150, the tubes ø 30 x 5 mm are joined by fins and form a membrane shield. According to the maps of tube wall thickness, in the zone of the highest heat load, sectors of the shield were sampled in the places where the tube wall thickness was equal or greater than 4.3 mm, i.e. the minimum calculation thickness, according to the specifications given by the boiler manufacturer. It means that the corrosive loss could be determined as small, in spite of a long operation time (more than 60,000 hours.Findings: The authors have determined structure and chemical and phase compositions of products and deposits forming in the radiant tubes in the regions of low corrosive losses after long-lasting operation (up to 60,000 hours. Then, they discussed a mechanism of formation of a compact layer protecting a steel surface against excessive oxidation under combustion gases.Practical implications: The layer on the tubes with small losses of wall thickness are characterized by the following properties: good compactness, very good adhesion to the metallic base, low amount of sulfur, especially in magnetite, no aggressive components at the phase boundary product – steel, small development of the phase boundary product-steel. Owing to those properties, even presence of sulfur in the products do not reduce their passivation qualities.Originality/value: Determination of the oxidation product layer of the steel applied for the radiant tubes.

  15. Production and testing of tubes for nuclear boiler steam generators

    International Nuclear Information System (INIS)

    Vallourec, second pipe manufacturer in Europe, has developed a workshop for the production of nuclear heat exchanger tubes in its Montbard plant. This workshop, by its special construction, production engineering and handling procedures, has attained nuclear standards and can produce U-bended tubes from diameter 12 to 25 mm with a maximum length of 36 meters. Its annual out-put is 1.500.000 meters. The final dimensions are obtained by a cold rolling procedure, followed by an outside and inside degreasing, a solution annealing in a controlled atmosphere continuous type furnace, a surface grinding and an inside surface conditionning. The non-destructive tests: eddy currents, ultrasonic tests and thickness mesures are recorded on a single tube basis. The curving and packing procedures have been specially developed for this production

  16. Some aspects of metallurgical assessment of boiler tubes-Basic principles and case studies

    International Nuclear Information System (INIS)

    Microstructural changes in boiler tubes during prolong operation at high temperature and pressure decrease load bearing capacity limiting their useful lives. When the load bearing capacity falls below a critical level depending on operating parameters and tube geometry, failure occurs. In order to avoid such failures mainly from the view point of economy and safety, this paper describes some basic principles behind remaining life assessment of service exposed components and also a few case studies related to failure of a reheater tube of 1.25Cr-0.5Mo steel, a carbon steel tube and final superheater tubes of 2.25Cr-1Mo steel and remaining creep life assessment of service exposed but unfailed platen superheater and reheater tubes of 2.25Cr-1Mo steel. Sticking of fly ash particles causing reduction in effective tube wall thickness is responsible for failure of reheater tubes. Decarburised metal containing intergranular cracks at the inner surface of the carbon steel tube exhibiting a brittle window fracture is an indicative of hydrogen embrittlement responsible for this failure. In contrast, final superheater tube showed that the failure took place due to short-term overheating. The influence of prolong service revealed that unfailed reheater tubes exhibit higher tensile properties than that of platen superheater tubes. In contrast both the tubes at 50 MPa meet the minimum creep rupture properties when compared with NRIM data. The remaining creep life of platen superheater tube as estimated at 50 MPa and 570 deg. C (1058 oF) is more than 10 years and that of reheater tube at 50 MPa and 580 deg. C (1076 oF) is 9 years

  17. Cracking and Corrosion of Composite Tubes in Black Liquor Recovery Boiler Primary Air Ports

    Energy Technology Data Exchange (ETDEWEB)

    Keiser, James R.; Singbeil, Douglas L.; Sarma, Gorti B.; Kish, Joseph R.; Yuan, Jerry; Frederick, Laurie A.; Choudhury, Kimberly A.; Gorog, J. Peter; Jetté, Francois R.; Hubbard, Camden R.; Swindeman, Robert W.; Singh, Prett M.; Maziasz, Phillip J.

    2006-10-01

    Black liquor recovery boilers are an essential part of kraft mills. Their design and operating procedures have changed over time with the goal of providing improved boiler performance. These performance improvements are frequently associated with an increase in heat flux and/or operating temperature with a subsequent increase in the demand on structural materials associated with operation at higher temperatures and/or in more corrosive environments. Improvements in structural materials have therefore been required. In most cases the alternate materials have provided acceptable solutions. However, in some cases the alternate materials have solved the original problem but introduced new issues. This report addresses the performance of materials in the tubes forming primary air port openings and, particularly, the problems associated with use of stainless steel clad carbon steel tubes and the solutions that have been identified.

  18. EXPERIMENTAL INVESTIGATION OF NICKEL ALUMINIDE (NI3AL) NANOSTRUCTURED COATED ECONOMISER TUBE IN BOILER

    OpenAIRE

    * Gokulakannan A, Karuppasamy K

    2016-01-01

    Thermal Power Stations all over the world are facing the problem of boiler tube leakage frequently. The consequences of which affects the performance of power plant and huge amount of money loss. Hot corrosion and erosion are recognized as serious problems in coal based power generation plants in India. The maximum number of cause of failure in economizer unit is due to flue gas erosion. The corrosion resistant coatings used conventionally are having some limitations like degradation of the c...

  19. Failure Investigation of Radiant Platen Superheater Tube of Thermal Power Plant Boiler

    Science.gov (United States)

    Ghosh, D.; Ray, S.; Mandal, A.; Roy, H.

    2015-04-01

    This paper highlights a case study of typical premature failure of a radiant platen superheater tube of 210 MW thermal power plant boiler. Visual examination, dimensional measurement and chemical analysis, are conducted as part of the investigations. Apart from these, metallographic analysis and fractography are also conducted to ascertain the probable cause of failure. Finally it has been concluded that the premature failure of the super heater tube can be attributed to localized creep at high temperature. The corrective actions has also been suggested to avoid this type of failure in near future.

  20. Creep properties of electric resistance welded boiler tubes under internal pressure

    International Nuclear Information System (INIS)

    Creep rupture tests on electric resistance welded (ERW) tubular specimens of carbon steel and 1% Cr-0.5% Mo steel and burst tests on thickness-deviated tubular specimens of carbon steel are described. Also, changes of structures and mechanical properties of 1% Cr-0.5% Mo steel tubes after exposure to 5500C for up to 10,000 hours under a tensile hoop stress of 108 MPa are described. The creep rupture properties of ERW boiler tubes were proved to be quite comparable to those of seamless tubes, and the slightest deviation in wall thickness was shown to affect the internal pressure rupture behavior. Changes of structures at welded portion of ERW 1% Cr-0.5% Mo steel tubes were as same as those of base metal

  1. Investigations of the Failure in Boilers Economizer Tubes Used in Power Plants

    Science.gov (United States)

    Moakhar, Roozbeh Siavash; Mehdipour, Mehrad; Ghorbani, Mohammad; Mohebali, Milad; Koohbor, Behrad

    2013-09-01

    In this study, failure of a high pressure economizer tube of a boiler used in gas-Mazut combined cycle power plants was studied. Failure analysis of the tube was accomplished by taking into account visual inspection, thickness measurement, and hardness testing as well as microstructural observations using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and x-ray diffraction (XRD). Optical microscopy images indicate that there is no phase transformation during service, and ferrite-pearlite remained. The results of XRD also revealed Iron sulfate (FeSO4) and Iron hydroxide sulfate (FeOH(SO4)) phases formed on the steel surface. A considerable amount of Sulfur was also detected on the outer surface of the tube by EDS analysis. Dew-point corrosion was found to be the principal reason for the failure of the examined tube while it has been left out-of-service.

  2. Iron aluminide weld overlay coatings for boiler tube protection in coal-fired low NOx boilers

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-01

    Iron aluminide weld overlay coatings are currently being considered for enhanced sulfidation resistance in coal-fired low NO{sub x} boilers. The use of these materials is currently limited due to hydrogen cracking susceptibility, which generally increases with an increase in aluminum concentration of the deposit. The overall objective of this program is to attain an optimum aluminum content with good weldability and improved sulfidation resistance with respect to conventional materials presently in use. Research has been initiated using Gas Tungsten Arc Welding (GTAW) in order to achieve this end. Under different sets of GTAW parameters (wire feed speed, current), both single and multiple pass overlays were produced. Characterization of all weldments was conducted using light optical microscopy, scanning electron microscopy, and electron probe microanalysis. Resultant deposits exhibited a wide range of aluminum contents (5--43 wt%). It was found that the GTAW overlays with aluminum contents above {approximately}10 wt% resulted in cracked coatings. Preliminary corrosion experiments of 5 to 10 wt% Al cast alloys in relatively simple H{sub 2}/H{sub 2}S gas mixtures exhibited corrosion rates lower than 304 stainless steel.

  3. Design of an ion transport membrane reactor for application in fire tube boilers

    International Nuclear Information System (INIS)

    A design of an ITM (ion transport membranes) reactor is introduced in a two-pass fire tube boiler furnace to produce steam for power generation toward the ZEPP (zero emission power plant) applications. Oxygen separation, combustion and heat exchange occur in the first pass containing the multiple-units ITM reactor. In the second pass, heat exchange between the combustion gases and the surrounding water at 485 K (Psat = 20 bar) occurs mainly by convection. The emphasis is to extract sufficient oxygen for combustion while maintaining the reactor size as compact as possible. Based on a required power in the range of 5–8 MWe, the fuel and gases flow rates were calculated. Accordingly, the channel width was determined to maximize oxygen permeation flux and keep the viscous pressure drop within a safe range for fixed reactor length of 1.8 m. Three-dimensional simulations were conducted for both counter and co-current flow configurations. Counter-current flow configuration proved its suitability in fire tube boilers for steam generation over the co-current flow configuration. The resultant reactor consists of 12,500 ITM units with a height of 5 m, membrane surface area of 2700 m2 and a total volume of 45.45 m3. - Highlights: • A novel two-path fire tube boiler design is presented utilizing ITMs (ion transport membranes). • A new multi-unit ITM reactor design for boiler furnace substitution is presented. • Flow rates have been optimized for maximum oxygen flux and power generation. • Counter-current flow configuration is much more efficient than co-current flow. • Total number of ITM units was calculated to produce power of 5:8 MWe

  4. Surface chemistry interventions to control boiler tube fouling

    International Nuclear Information System (INIS)

    The adsorption of ammonia, morpholine, ethanolamine, and dimethylamine onto the surfaces of colloidal magnetite and hematite was measured at 25oC. The effect of the adsorption on the surface potential was quantified by measuring the resulting shift in the isoelectric point of the corrosion products and by the direct measurement of the surface interaction force between the corrosion products and Inconel 600. These measurements have served to support the hypothesis that adsorption of amine affects the magnetite deposition rate by lowering the force of repulsion between magnetite and the surface of Inconel 600. The deposition rate of hematite increased as the oxygen concentration increased. A mechanism to account for enhanced deposition rates at high mixture qualities (> 0.35) has been identified and shown to predict behaviour that is consistent with both experimental and plant data. As a result of this investigation, several criteria are proposed to reduce the extent of corrosion product deposition on the tube bundle. Low hematite deposition is favoured by a low concentration of dissolved oxygen, and low magnetite deposition is favoured by choosing an amine for pH control that has little tendency to adsorb onto the surface of magnetite. To minimize adsorption the amine should have a high base strength and a large 'footprint' on the surface of magnetite. To prevent enhanced deposition at high mixture qualities, it is proposed that a modified amine be used that will reduce the surface tension or the elasticity of the steam-water interface or both

  5. An advanced maintenance advisory and surveillance system for boiler tubes - AMASS

    Energy Technology Data Exchange (ETDEWEB)

    Tomkins, A.B. [ERA Technology Ltd, Leatherhead (United Kingdom)

    1998-12-31

    In a recently completed European collaborative project, the aim was to address the issue of boiler tube failures and thereby plant availability. The reduction of forced outages due to component failures and the reduction of planned outages for preventative maintenance can both contribute in this respect. It has been possible to assess tube degradation due to erosion, corrosion and overheating through the use of on-line techniques (thin layer activation, corrosion probes and novel temperature sensors) and off-line techniques (cold air velocity measurements, laser shearography and measurements of steam side oxide) which have been developed in the project. These techniques have been demonstrated on an oil fired boiler in Portugal and a coal fired unit in Spain. The output from the monitoring techniques has been integrated in the AMASS maintenance advisory and surveillance system. This is a computerised system comprising a spatial database with add-on tools designed to assess data from individual monitors and to provide the user with information on tube life utilisation rates and the probability of tube failure occurring. A description of the monitoring techniques will be described along with some of the results of demonstrating them in the field. Also an overview of the computerized system and the way in which it works will be given along with examples of how it can be used to assist with preventative maintenance and to help avoid unplanned outages. (orig.) 10 refs.

  6. Surface chemistry interventions to control boiler tube fouling - Part II

    International Nuclear Information System (INIS)

    This is the third in a series of reports from an investigation co-funded by the Electric Power Research Institute (EPRI) and by Atomic Energy of Canada Limited (AECL) into the effectiveness of alternative amines for controlling the rate of tube-bundle fouling under steam generator (SG) operating conditions. The objectives of this investigation are to determine whether the fouling rate depends on the amine used for pH control, to identify those factors that influence the effectiveness, and use this information to optimize the selection of an amine for chemistry control and deposit control in the steam cycle and steam generator, respectively. Work to date has demonstrated that the rate of particle deposition under steam generator operating conditions is strongly influenced by surface chemistry (Turner et al., 1997; Turner et al., 1999). This dependence upon surface chemistry is illustrated by the difference between the deposition rates measured for hematite and magnetite, and by the dependence of the particle deposition rate on the amine used for pH control. Deposition rates of hematite were found to be more than 10 times greater than those for magnetite under similar test conditions (Turner et al., 1997). At 270oC and pHT 6.2, the surfaces of hematite and magnetite are predicted to be positively charged and negatively charged, respectively (Shoonen, 1994). Measurements of the point of zero charge (PZC) of magnetite at temperatures from 25oC to 290oC by Wesolowski et al. (1999) have confirmed that magnetite is negatively charged at the stated conditions. A PZC of 4.2 was measured for Alloy 600 at 25oC (Balakrishnan and Turner, un-published results), and its surface is expected to remain negatively charged for alkaline chemistry over the temperature range of interest. Therefore, there will be a repulsive force between the surfaces of magnetite particles and Alloy 600 at 270oC and pHT 6.2 that is absent for hematite particles depositing under the same conditions. This

  7. Utilization of coal-water fuels in fire-tube boilers. Final report, October 1990--August 1994

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, T.; Melick, T.; Morrison, D.

    1994-12-31

    The objective of this DOE sponsored project was to successfully fire coal-water slurry in a fire-tube boiler that was designed for oil/gas firing and establish a data base that will be relevant to a large number of existing installations. Firing slurry in a fire-tube configuration is a very demanding application because of the extremely high heat release rates and the correspondingly low furnace volume where combustion can be completed. Recognizing that combustion efficiency is the major obstacle when firing slurry in a fire-tube boiler, the program was focused on innovative approaches for improving carbon burnout without major modifications to the boiler. The boiler system was successfully designed and operated to fire coal-water slurry for extended periods of time with few slurry related operational problems. The host facility was a 3.8 million Btu/hr Cleaver-Brooks fire-tube boiler located on the University of Alabama Campus. A slurry atomizer was designed that provided outstanding atomization and was not susceptible to pluggage. The boiler was operated for over 1000 hours and 12 shipments of slurry were delivered. The new equipment engineered for the coal-water slurry system consisted of the following: combustion air and slurry heaters; cyclone; baghouse; fly ash reinjection system; new control system; air compressor; CWS/gas burner and gas valve train; and storage tank and slurry handling system.

  8. ANSYS Fluent Modelling of an Underexpanded Supersonic Sootblower Jet Impinging into Recovery Boiler Tube Geometries

    Science.gov (United States)

    Doroudi, Shahed

    Sootblowers generate high pressure supersonic steam jets to control fireside deposition on heat transfer tubes of a kraft recovery boiler. Sootblowing is energy expensive, using 3-12% of the mill's total steam production. This motivates research on the dynamics of sootblower jet interaction with tubes and deposits, to optimize their use. A CFD investigation was performed using ANSYS Fluent 15.0 to model three-dimensional steady-state impingement of a Mach 2.5 mildly underexpanded (PR 1.2) air jet onto arrays of cylindrical tubes with and without fins, at various nozzle-to-tube centerline offsets. A free jet and four impingement cases for each of the economizer and generating bank geometries are compared to experimental visualizations. Pressure distributions on impinging surfaces suggest that the fins in the economizer produce a reduced but uniform sootblowing force. Pressure contours along the tubes (in the vertical direction) show a sharp decline one tube diameter away from the jet mid-plane.

  9. FAILURE ANALYSIS IN TUBING OF AIR PREHEATER OF BOILER FROM A SUGARCANE MILL

    Directory of Open Access Journals (Sweden)

    Joner Oliveira Alves

    2014-10-01

    Full Text Available The increased demand for energy from sugarcane bagasse has made the sugar and alcohol mills search alternatives to reduce maintenance of the boilers, releasing more time to the production. The stainless steel use has become one of the main tools for such reduction. However, specification errors can lead to premature failures. This work reports the factors that led tubes of AISI 409 stainless steel fail after half season when applied in a air preheater of boiler from a sugarcane mill. In such application, the AISI 304 lasts about 15 seasons and the carbon steel about 3. A tube sent by the sugar mill was characterized by wet chemical analysis, optical microscopy and EDS. Results indicated chloride formation on the internal walls of the tube, which combined with the environment, accelerated the corrosion process. The carbon steel showed high lifetime due to a 70% higher thickness. Due to the work condictions is recommended the use of stainless steels with higher corrosion resistance, such as the traditional AISI 304 or the ferritic AISI 444, the last presents better thermal exchange.

  10. Creep-Rupture Behavior and Recrystallization in HR6W and Haynes Alloy 230 Cold-Bent Boiler Tubing for Ultrasupercritical (USC) Steam Boiler Applications

    Energy Technology Data Exchange (ETDEWEB)

    Shingledecker, John P [ORNL

    2007-01-01

    Creep-rupture experiments were conducted on HR6W and Haynes 230, candidate Ultrasupercritical (USC) alloys, tubes to evaluate the effects of cold-work and recrystallization during high-temperature service. These creep tests were performed by internally pressurizing cold-bent boiler tubes at 775 C for times up to 8000 hours. The bends were fabricated with cold-work levels beyond the current ASME Boiler and Pressure Vessel (ASME B&PV) Code Section I limits for austenitic stainless steels. Destructive metallographic evaluation of the crept tube bends was used to determine the effects of cold-work and the degree of recrystallization. The metallographic analysis combined with an evaluation of the creep and rupture data suggest that solid-solution strengthened nickel-based alloys can be fabricated for high-temperature service at USC conditions utilizing levels of cold-work higher than the current allowed levels for austenitic stainless steels.

  11. Temperature prediction method for superheater and reheater and reheater tubes of fossil power plant boiler during operation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bum Shin; Song, Gee Wook; Yoo, Seong Yeon [Chungnam Nat' l Univ., Daejeon (Korea, Republic of)

    2012-05-15

    The superheater and reheater tubes of a heavy load fossil power plant boiler can be damaged by overheating, and therefore, the degree of overheating is assessed by measuring the oxide scale thickness inside the tube during outages. The tube temperature prediction from the oxide scale thickness measurement is necessarily accompanied by destructive tube sampling, and the result of tube temperature prediction cannot be expected to be accurate unless the selection of the overheated point is precise and the initial operation tube temperature has been obtained. In contrast, if the tube temperature is to be predicted analytically, considerable effort (to carry out the analysis of combustion, radiation, convection heat transfer, and turbulence fluid dynamics of the gas outside the tube) is required. In addition, in the case of analytical tube temperature prediction, load changes, variations in the fuel composition, and operation mode changes are hardly considered, thus impeding the continuous monitoring of the tube temperature. This paper proposes a method for the short term prediction of tube temperature; the method involves the use of boiler operation information and flow network analysis based tube heat flux. This method can help in high temperature damage monitoring when it is integrated with a practical tube damage assessment method such as the Larson Miller Parameter.

  12. The creep life of superheater and reheater tubes under varying pressure conditions in operational boilers

    International Nuclear Information System (INIS)

    The first of each manufacturer's 500 MW boilers supplied to the CEGB (Central Electricity Generating Board) have been subjected to an extensive programme of tests for performance optimization and safe operation. Around 250 thermocouples on superheater and reheater tubes have in each case been monitored as part of the exercise. The readings are corrected and used to compute creep rupture damage based on internationally agreed stress rupture data and a simple cumulative damage concept. Comparison of the design creep rupture life and the cumulative life consumed has in several applications been invaluable in influencing operating procedures and arranging tube modifications or replacements, so that loss of generation by creep rupture failure is minimized. (author)

  13. Stress and integrity analysis of steam superheater tubes of a high pressure boiler

    Directory of Open Access Journals (Sweden)

    Neves Daniel Leite Cypriano

    2004-01-01

    Full Text Available Sources that can lead to deterioration of steam superheater tubes of a high pressure boiler were studied by a stress analysis, focused on internal pressure and temperature experienced by the material at real operating conditions. Loss of flame control, internal deposits and unexpected peak charge are factors that generate loads above the design limit of tube materials, which can be subjected to strain, buckling, cracks and finally rupture in service. To evaluate integrity and dependability of these components, the microstructure of selected samples along the superheater was studied by optical microscopy. Associated with this analysis, dimensional inspection, nondestructive testing, hardness measurement and deposit examination were made to determine the resultant material condition after twenty three years of operation.

  14. Thermal shocks in solar boiler tubes and mechanical tolerance to heating velocity

    International Nuclear Information System (INIS)

    The boiler circular cross-section tubes are cooled by an internal flow and are subjected to a non uniform heat flux around their outer circumference that changes very rapidly with time. Thus thermal shocks can develop in the thickness of tube walls and may cause brittle fracture or fatigue damage. We solve the corresponding thermoelastic problem. The determination of temperature distribution through the wall thickness requires the solution of one-dimensional transient heat equation obtained by performing a Fourier expansion in the angular variable. For each harmonic, Galerkin's method with respect to the radial coordinate together with a finite difference scheme with respect to time permit to completely discretize the associated equation. (orig.)

  15. Oxidation study by Moessbauer and optic microscopy of steels from boiler tubes used in sugar industry

    International Nuclear Information System (INIS)

    Optic microscopy and Moessbauer spectroscopy were used to study the fail and the inner rusted surface of two boiler tubes used in the sugar industry, respectively. The studied tubes, of the type ASTM A 192, were found to have cracks. By optic microscopy it was observed that the failure begins in the inner surface with circumferential cracking. Also, inside and around the surface close to the cracks a rusted layer was detected. Powder from these layers was collected for Moessbauer spectroscopy analysis. By this method the presence of two or three types of Fe oxides such as wuestite, magnetite and hematite, was proved. These results permit to conclude that the failure mechanism was the thermal fatigue due to a hot work in an O2 -rich vapor atmosphere. The rusted products are stable at high temperatures

  16. Development of Computational Capabilities to Predict the Corrosion Wastage of Boiler Tubes in Advanced Combustion Systems

    Energy Technology Data Exchange (ETDEWEB)

    Kung, Steven; Rapp, Robert

    2014-08-31

    coal-fired boilers resulting from the coexistence of sulfur and chlorine in the fuel. A new corrosion mechanism, i.e., “Active Sulfidation Corrosion Mechanism,” has been proposed to account for the accelerated corrosion wastage observed on the furnace walls of utility boilers burning coals containing sulfur and chlorine. In addition, a second corrosion mechanism, i.e., “Active Sulfide-to-Oxide Corrosion Mechanism,” has been identified to account for the rapid corrosion attack on superheaters and reheaters. Both of the newly discovered corrosion mechanisms involve the formation of iron chloride (FeCl2) vapor from iron sulfide (FeS) and HCl, followed by the decomposition of FeCl2 via self-sustaining cycling reactions. For higher alloys containing sufficient chromium, the attack on superheaters and reheaters is dominated by Hot Corrosion in the presence of a fused salt. Furthermore, two stages of the hot corrosion mechanism have been identified and characterized in detail. The initiation of hot corrosion attack induced by molten sulfate leads to Stage 1 “acidic” fluxing and re-precipitation of the protective scale formed initially on the deposit-covered alloy surfaces. Once the protective scale is penetrated, Stage 2 Hot Corrosion is initiated, which is dominated by “basic” fluxing and re-precipitation of the scale in the fused salt. Based on the extensive corrosion information generated from this project, corrosion modeling was performed using non-linear regression analysis. As a result of the modeling efforts, two predictive equations have been formulated, one for furnace walls and the other for superheaters and reheaters. These first-of-the-kind equations can be used to estimate the corrosion rates of boiler tubes based on coal chemistry, alloy compositions, and boiler operating conditions for advanced boiler systems.

  17. Thermographic imaging of material loss in boiler water-wall tubing by application of scanning line source

    Science.gov (United States)

    Cramer, K. Elliott; Winfree, William P.

    2000-06-01

    Localized wall thinning due to corrosion in utility boiler water-wall tubing is a significant inspection concern for boiler operators. Historically, conventional ultrasonics has been used for inspection of these tubes. This technique has proven to be very manpower and time intensive. This has resulted in a 'spot check' approach to inspections, documenting thickness measurements over a relatively small percentage of the total boiler wall area. NASA Langley Research Center has developed a thermal NDE technique designed to image and quantitatively characterize the amount of material thinning present in steel tubing. The technique involves the movement of a thermal line source across the outer surface of the tubing followed by an infrared imager at a fixed distance behind the line source. Quantitative images of the material loss due to corrosion are reconstructed from measurements of the induced surface temperature variations. This paper will present a discussion of the development of the thermal imaging system as well as the techniques used to reconstruct images of flaws. The application of the thermal line source coupled with the analysis technique represents a significant improvement in the inspection speed for large structures such as boiler water-walls. A theoretical basis for the technique will be presented which explains the quantitative nature of the technique. Further, a dynamic calibration system will be presented for the technique that allows the extraction of thickness information from the temperature data. Additionally, the results of applying this technology to actual water-wall tubing samples and in situ inspections will be presented.

  18. Remaining Life Analysis of Boiler Tubes on Behalf of Hoop Stresses Produced During Operation of Power Plant

    Directory of Open Access Journals (Sweden)

    Mohd. Zeeshan Gauri

    2014-07-01

    Full Text Available Boiler tube material plays an important role in efficient power generation from a fossil fuel power plant. In order to meet out the gap between fluids to increase heat available per unit mass flow of steam. Waste heat utilization phenomenon is a big challenge on fossil fuel power plants as after use of high grade coal in thermal power plants the efficiency of power plants is not at the level of required value. Clean and efficient power generation with economical aspects is the basic need of growing power generation plants to justify the quality of power and clean power generation. Life analysis technique to calculate remaining life of boiler tubes at critical zones of high temperature requires much attention and is an important hypothesis in research field. Generation of repetitive and fluctuating stress during flow of high temperature and pressure fluid require proper attention on the methodology to be used to calculate the efficiency of system and absorption efficiency of tube material. In this paper complete mathematical analysis of boiler tubes is conducted for calculation of remaining life of boiler tubes, Hoop stress values are calculated and used with mathematical tool to calculate the efficiency. Hoop stress based calculation of efficiency is more reliable and may give more accurate and practical aspects based results.

  19. Corrosion/erosion detection of boiler tubes utilizing pulsed infrared imaging

    Science.gov (United States)

    Bales, Maurice J.; Bishop, Chip C.

    1995-05-01

    This paper discusses a new technique for locating and detecting wall thickness reduction in boiler tubes caused by erosion/corrosion. Traditional means for this type of defect detection utilizes ultrasonics (UT) to perform a point by point measurement at given intervals of the tube length, which requires extensive and costly shutdown or `outage' time to complete the inspection, and has led to thin areas going undetected simply because they were located in between the sampling points. Pulsed infrared imaging (PII) can provide nearly 100% inspection of the tubes in a fraction of the time needed for UT. The IR system and heat source used in this study do not require any special access or fixed scaffolding, and can be remotely operated from a distance of up to 100 feet. This technique has been tried experimentally in a laboratory environment and verified in an actual field application. Since PII is a non-contact technique, considerable time and cost savings should be realized as well as the ability to predict failures rather than repairing them once they have occurred.

  20. Study of Microstructure Degradation of Boiler Tubes Due To Creep for Remaining Life Analysis

    Directory of Open Access Journals (Sweden)

    Kavita Sankhala

    2014-07-01

    Full Text Available In the current scenario of power shortage in India, the main objective is to ensure availability of power plant and increasing its reliability. During assessment ,testing and inspection a simple question has to be asked again and again‖ How long the particular power plants can be operated safely and cost-effectively with satisfying increased requirements and operational availability with reduced pollutant emissions, even after their designed life. So to answer this important question regarding the operational capability of the existing plant the remaining life analysis (RLA has to be done. The condition of the plant equipments can be assessed only by way of a RLA methodology. On the basis of RLA proper decision can be made about the plants safety and availability. There are many methods to carry out the RLA of the critical components out of which ―microstructure study‖ is a method. In this paper we have tried to outline the RLA procedures and review the various damage mechanisms based on microstructure study. It is also presents the microstructure changes and properties of 106720 service hour exposed boiler tube in a 120 MW boiler of a thermal power plant.

  1. Microstructural degradation of boiler tube steels under long term exposure to high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Salonen, J.; Auerkari, P. [VTT Manufacturing Technology, Espoo (Finland)

    1996-12-31

    Thermal microstructural degradation was investigated by isothermal annealing of samples from boiler tube steels St 35.8, 15 Mo 3, 13 CrMo 44, 10 CrMo 9 10 and X20 CrMoV 12 1 in the temperature range 600-780 deg C for up to 2 000 h. Optical and scanning electron microscopy and hardness testing were used for characterising the micro structural changes and their time-temperature dependence. The results suggest a simple and consistent time-temperature dependence for all investigated materials, expected to apply also to long term service beyond the annealing time range of the present work. This would allow assessment of the in-service thermal exposure from the observed microstructure. A collection of micro graphs has been prepared for this purpose, to aid in classifying and evaluating the observed microstructural state in terms of isothermal exposure to high temperature. (orig.) (6 refs.)

  2. Application of a new thermoelastic thick shell theory to solar boiler tubes

    International Nuclear Information System (INIS)

    The classical thin shell theory relies on Kirchhoff's hypotheses which notably lead one to neglect normal stresses in the 'thickness direction', shearing stresses on surfaces parallel to the mean surface, warping and extension of fibers normal to the same surface. As is well known, the thermoelastic constitutive equations contradict these assumptions, which are no longer acceptable when the shell is not 'very thin' and when the thermal gradient through the thickness becomes noticeable. The thick shell theory proposed here was initially meant to describe the behavior of solar boiler tubes, but it is also applicable to piping elements encountered in most energy conversion systems, such as fossil-fired power plants, nuclear reactors, etc. For the sake of simplicity, the presentation is restricted to the study of a long tube subjected to an intense heat flux on one side; this tube carries a working fluid and the temperature distribution in the metal is not axisymmetric. By generalizing the asymptotic expansion theory of Reiss to the thermoelastic case, it is shown that higher order theory immediately following the classical thin shell approach should be based upon a displacement field whose radial component is a second order polynomial in the thickness coordinate z, whereas the tangential component is a third order polynomial in the same coordinate; the coefficients of these two polynomials are the generalized displacements of the theory. Then a 'generalized' Kirchhoff hypothesis is used, which consists in requiring the shearing stresses or deformations to vanish on the inner and outer tube surfaces only. This allows one to express two of the generalized displacements in terms of the others. The so-constructed displacement distribution is sufficiently general to account for warping and extension of fibers normal to the mean surface as well as shearing on surfaces z = constant; these effects are usually neglected. (orig.)

  3. Remaining Life Analysis of Boiler Tubes on Behalf of Hoop Stresses Produced During Operation of Power Plant

    OpenAIRE

    Mohd. Zeeshan Gauri; Kavita Sankhala

    2014-01-01

    Boiler tube material plays an important role in efficient power generation from a fossil fuel power plant. In order to meet out the gap between fluids to increase heat available per unit mass flow of steam. Waste heat utilization phenomenon is a big challenge on fossil fuel power plants as after use of high grade coal in thermal power plants the efficiency of power plants is not at the level of required value. Clean and efficient power generation with economical aspects is the...

  4. High-Temperature Corrosion of Protective Coatings for Boiler Tubes in Thermal Power Plants

    Institute of Scientific and Technical Information of China (English)

    XU Lianyong; JING Hongyang; HUO Lixing

    2005-01-01

    High-temperature corrosion is a serious problem for the water-wall tubes of boilers used in thermal power plants. Oxidation, sulfidation and molten salt corrosion are main corrosion ways.Thereinto, the most severe corrosion occurs in molten salt corrosion environment. Materials rich in oxides formers, such as chromium and aluminum, are needed to resist corrosion in high-temperature and corrosive environment, but processability of such bulk alloys is very limited. High velocity electric arc spraying (HVAS) technology is adopted to produce coatings with high corrosion resistance. By comparison, NiCr (Ni-45Cr-4Ti) is recommended as a promising alloy coating for the water-wall tubes, which can even resist molten salt corrosion attack. In the study of corrosion mechanism, the modern material analysis methods, such as scanning electron microscopy (SEM), X-ray diffractometry (XRD) and energy dispersive spectrometry (EDS), are used. It is found that the corrosion resistances of NiCr and FeCrAI coatings are much better than that of 20g steel, that the NiCr coatings have the best anti-corrosion properties, and that the NiCr coatings have slightly lower pores than FeCrAI coatings.It is testified that corrosion resistance of coatings is mainly determined by chromium content, and the microstructure of a coating is as important as the chemical composition of the material. In addition, the fracture mechanisms of coatings in the cycle of heating and cooling are put forward. The difference of the thermal physical properties between coatings and base metals results in the thermal stress inside the coatings. Consequently, the coatings spall from the base metal.

  5. Causes and solutions for cracking of coextruded and weld overlay floor tubes in black liquor recovery boilers

    Energy Technology Data Exchange (ETDEWEB)

    Keiser, J.R.; Taljat, B.; Wang, X.L. [and others

    1998-09-01

    Cracking of coextruded, black liquor recovery boiler floor tubes is both a safety and an economic issue to mill operators. In an effort to determine the cause of the cracking and to identify a solution, extensive studies, described in this and three accompanying papers, are being conducted. In this paper, results of studies to characterize both the cracking and the chemical and thermal environment are reported. Based on the results described in this series of papers, a possible mechanism is presented and means to lessen the likelihood of cracking or to totally avoid cracking of floor tubes are offered.

  6. Erosion in steam general tubes in boiler and ID fans in coal fired FBC power plant

    International Nuclear Information System (INIS)

    The FBC (Fluidized Bed Combustion) is a technique used to make solid particles behave like fluid and grow very fast for the power generation using low grade coal. Due to its merits, first time this technology has been introduced in Pakistan by installing 3 X 50 MW power plants at Khanote. Fluidized beds have long been used for the combustion of low-quality, difficult fuels and have become a rapidly developing technology for the clean burning of coal. The FBC Power Plant at Khanote has been facing operational and technical problems, resulting frequently shut down of generation units, consequently facing heavy financial losses. This study reveals that due to the presence of high percentage of silica in the lime stone that are further distributed in the bottom ash, fly ash and re-injection material, the generation tubes in the boiler and wings/blades of ID (Induced Draft) fans were eroded. In addition, filter bags were also ruptured; resulting frequent shut down of power plant units. (author)

  7. Erosion in Steam General Tubes in Boiler and ID Fans in Coal Fired FBC Power Plant

    Directory of Open Access Journals (Sweden)

    Shaheen Aziz

    2012-01-01

    Full Text Available The FBC (Fluidized Bed Combustion is a technique used to make solid particles behave like fluid and grow very fast for the power generation using low grade coal. Due to its merits, first time this technology has been introduced in Pakistan by installing 3x50 MW power plants at Khanote. Fluidized beds have long been used for the combustion of low-quality, difficult fuels and have become a rapidly developing technology for the clean burning of coal. The FBC Power Plant at Khanote has been facing operational and technical problems, resulting frequently shut down of generation units, consequently facing heavy financial losses. This study reveals that due to the presence of high percentage of silica in the lime stone that are further distributed in the bottom ash, fly ash and re-injection material, the generation tubes in the boiler and wings/blades of ID (Induced Draft fans were eroded. In addition, filter bags were also ruptured; resulting frequent shut down of power plant units.

  8. The Boiler Tube Wall Thickness Quantitative Evaluation Fusing the Magnetic and Ultrasonic Technique

    Institute of Scientific and Technical Information of China (English)

    SONG Xiaochun; HUANG Songling; ZHAO Daxing

    2006-01-01

    Wall thickness is always a key index for boiler tube inspection in power plant, in order to improve the inspection efficiency and accuracy, a new method fusing the magnetic and ultrasonic technique was proposed. The magnetic technique was used to do full inspection and locate the flaws, and the ultrasonic was employed to implement further quantitative inspection accurately. After comparing the precision of the polynomial, exponential and logarithmic function, the polynomial model was selected to fit the relations between the wall thickness and the peak value of magnetic signals, and the data measured by ultrasonic thickness meter was used to calibrate the model parameters online, the defect depth can be sized quickly. The experimental results demonstrate that the model used in this system has better accuracy than the statistics relation model clearly, and it is also suitable for defect evaluation real-time. Moreover, it is unnecessary to have much more experimental data for the curve fitting technology, so it has better practicability than the other methods.

  9. Diagnosis of Heat Exchanger Tube Failure in Fossil Fuel Boilers Through Estimation of Steady State Operating Conditions

    International Nuclear Information System (INIS)

    Estimation of operating conditions for fossil fuel boiler heat exchangers is often required due to changes in working conditions, design modifications and especially for monitoring performance and failure diagnosis. Regular heat exchangers in fossil fuel boilers are composed of tube banks through which water or steam flow, while hot combustion (flue) gases flow outside the tubes. This work presents a top-down approach to operating conditions estimation based on field measurements. An example for a 350 MW unit superheater is thoroughly discussed. Integral calculations based on measurements for all unit heat exchangers (reheaters, superheaters) were performed first. Based on these calculations a scheme of integral conservation equations (lumped parameter) was then formulated at the single tube level. Steady state temperatures of superheater tube walls were obtained as a main output, and were compared to the maximum allowable operating temperatures of the tubes material. A combined lumped parameter - CFD (Computational Fluid Dynamics, FLUENT code) approach constitutes an efficient tool in certain cases. A brief report of such a case is given for another unit superheater. We conclude that steady state evaluations based on both integral and detailed simulations are a valuable monitoring and diagnosis tool for the power generation industry

  10. Weldability of high strength Ni-based alloy USC141 as boiler tube for 700 C USC plant

    Energy Technology Data Exchange (ETDEWEB)

    Bao, G.; Sato, T. [Babcock-Hitachi K.K. Kure-shi, Hiroshima-ken (Japan); Imano, S.; Sato, J. [Hitachi, Ltd. Hitachi-shi, Ibaraki-ken (Japan); Uehara, T.; Toji, A. [Hitachi Metals, Ltd. Yasugi-shi, Shimane-ken (Japan)

    2007-07-01

    Recently the increase of steam temperature and pressure of power plant is required to enhance the thermal efficiency and reduce the CO{sub 2} emission. For the application to advanced USC (Ultra Super Critical) boiler with steam temperature around 700 C, the application of Ni-based alloy such as Alloy617 will be necessary. A new Ni-based alloy USC141 (20Cr-10Mo-2Ti-Al-bal.Ni) with excellent creep rupture strength and low thermal expansion has been developed by Hitachi Ltd. and Hitachi Metals Ltd. as the candidate material for 700 C USC turbine components. In present work, to investigate the possibility for boiler tube application of USC141, its weldability and high temperature strength properties were experimentally examined. The tested material as solution-treated condition shows higher creep rupture strength than that of Alloy617. GTAW (Gas Tungsten Arc Welding) trials of tubular specimen using NIMONIC263 filler wire were conducted successfully and the creep rupture strength of weld joint was as similar as that of parent metal. Therefore it is considered that USC141 has a promising potential as boiler tube candidate for 700 C class USC power plant. (orig.)

  11. Thermal design of horizontal tube boilers. Numerical and experimental investigation; Modelisation thermique de bouilleurs a tubes horizontaux. Etude numerique et validation experimentale

    Energy Technology Data Exchange (ETDEWEB)

    Roser, R.

    1999-11-26

    This work concerns the thermal design of kettle reboilers. 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 modeling of the two-phase flow in the boiler, which is a significant progress compared to current simplified methods. (author)

  12. Development of 18Cr-9Ni-W-Nb-V-N Austenitic Stainless Steel Tube for Thermal Power Boilers

    Science.gov (United States)

    Ishitsuka, Tetsuo; Mimura, Hiroyuki

    An 18Cr-9Ni-W-Nb-V-N austenitic stainless steel tube for thermal power boilers has been newly developed. The high temperature mechanical properties and corrosion resistance of the steel were investigated. The creep rupture strength of the developed steel is about 1.5 times as high as that of SUS347HTB, and is almost the same as that of Ka-SUS310J2TB at 650°C. This excellent creep strength of the steel is mainly due to solid solution strengthening by tungsten and nitrogen, and precipitation strengthening by nitrides of niobium and vanadium. The carbon content of the steel is reduced to 0.03% to improve intergranular corrosion resistance. The steam oxidation resistance and the high temperature corrosion resistance of the tube are almost the same as those of SUS347HTB. Weldability of the developed steel is superior to that of SUS304HTB and SUS310TB. Thus the developed steel is suitable for use as a material for superheater and reheater tubes of thermal power boilers.

  13. Use of Radioactive Tracers for Measuring the Density of the Emulsion (Water-Steam) Flowing in the Water-Wall Tubes of Industrial Boilers

    International Nuclear Information System (INIS)

    Introduction of a radioactive nuclide into the water offers a rapid procedure for diagnosing the functioning and properties of industrial boilers without altering the phenomena to be measured. The choice of radionuclide must satisfy strict criteria; after a large number of trials, a mixture of 186Re and 188Re obtained by neutron irradiation of natural rhenium was chosen. The background noise is measured at the time of the trials with the help of a system of three tubes placed in front of the boiler, or of one tube placed in an inspection chamber. The density of the emuision (water- steam) can be measured with an accuracy of between 10% and 15%. Trials were carried out on a boiler with a capacity of 3 tons of water operating under a pressure of 10kg/cm2 at 180°C. The emulsion density in several water-wall tubes was compared for different vapour flows, the density being measured along the whole length of the tube, which gives information on the thermal exchanges between the furnace and this tube. Trials will very soon be carried out on a power boiler belonging to Electricité de France (Creil Power Station). The personnel working around the boiler run no risk of irradiation since the quantities of radionuclide (10 to 25 μCi/litre of water) are small. The complete calculation of the isodose curves, verified by dosimetric measurements, shows that the dose 20 cm outside the boiler is below 90 mrads after 210 h, which is 6 or 7 times lower than the maximum tolerable dose. The dose is even smaller in the case of a large boiler. (author)

  14. Determining the parameters at which burnout occurs in the waterwall tubes of drum boilers

    Energy Technology Data Exchange (ETDEWEB)

    I.I. Belyakov [Central Boiler-Turbine Institute Research and Production Association (OAO TsKTI), St. Petersburg (Russian Federation)

    2007-09-15

    Parameters at which burnout occurs are presented that were obtained by measuring the temperature and heat fluxes during experiments carried out directly on a boiler. The results of a comparison between the obtained values and the data of investigations on a test facility are given.

  15. Industrial mastering the use of tube fining by high-frequency welding for gasproof boilers

    International Nuclear Information System (INIS)

    Results of introduction of 20 and 12Kh1MF steel tube fining by high-frequency welding are presented. Heat treatment effect on properties of joints is studied, mechanical tests, metallographical and electron-microscopic investigations are carried out. It is shown that weld method of fins to tubes with the help of high-frequency currents is characterized by universality that permits to produce fined tubes of practically any diameter with fins of any width, control of smooth tubes before the fins welding to them being provided. Studies of properties of fined tubes has shown high quality of welded joints carried out by high-frequency current heating

  16. Analysis of High-temperature Boiler Tube Failure for T91 &T22

    Institute of Scientific and Technical Information of China (English)

    SHU Guo-gang; DING Hui; ZHAO Yan-fen; XUE Fei; ZHAO Ling-song; ZHANG Lu; LIU Jiang-nan; WANG Zheng-pin

    2004-01-01

    The tube failures took place frequently in the superheater of 2x600MW units in a power plant. According to the condition of tube failures, the mechanical property and microstructure on running and failed tubes were tested and evaluated. The chemical composition and structure phase of inner oxide scale and deposit inside of the tubes were examined.The fractured surfaces of failed tube samples were observed. And the material examination was performed for original tube steels SA213-T91 and SA213-T22. The results show that raw materials of SA213-T91 and SA213-T22 tube in superheater are qualified. Besides, the characteristics of the SA213-T91 and SA213-T22 tube failure are typical short-term overheated rupture. The rupture temperature is located between two phase Ac1 ~ Ac3 of the two steels. It is recognized that putting SA213-T22 tubes in operation under the condition of long-term over heating causes the rupture of SA213-T91 and SA213-T22.

  17. Thermohydraulic characteristics of serpentine tubing in the boilers of gas cooled reactors under condition of rapid and slow depressurization

    International Nuclear Information System (INIS)

    In nuclear reactors of the Magnox or advanced gas Cooled type, serpentine tubing is used in some designs to generate steam in a once through arrangement. The calculation of accident conditions using two phase flow codes requires knowledge of the heat transfer behaviour of the boiler steam side. A series of experiments to study the blowdown characteristics of a typical serpentine boiler section was devised in order to validate the MARTHA section of the MACE code used by nuclear Electric. The tests were carried out on the Thermal Hydraulics Experimental Research Assembly (THERA) loop at Manchester University. Depressurization from an initial pressure of 60 bar, with fluid subcooling of 5 K, 50 K, and 100 K was controlled by discharging the test section contents through suitably chosen orifices to produce blowdown to 10% of the initial pressure over a time scale of 30 s to 3600 s. Pressures and temperatures in the serpentine were measured at average time intervals of approximately 1 s. (author)

  18. Corrosion behaviour of boiler tube materials during combustion of fuels containing Zn and Pb

    Energy Technology Data Exchange (ETDEWEB)

    Bankiewicz, D.

    2012-11-01

    Many power plants burning challenging fuels such as waste-derived fuels experience failures of the superheaters and/or increased waterwall corrosion due to aggressive fuel components already at low temperatures. To minimize corrosion problems in waste-fired boilers, the steam temperature is currently kept at a relatively low level which drastically limits power production efficiency. The elements found in deposits of waste and waste-derived fuels burning boilers that are most frequently associated with high-temperature corrosion are: Cl, S, and there are also indications of Br; alkali metals, mainly K and Na, and heavy metals such as Pb and Zn. The low steam pressure and temperature in waste-fired boilers also influence the temperature of the waterwall steel which is nowadays kept in the range of 300 deg C - 400 deg C. Alkali chloride (KCl, NaCl) induced high-temperature corrosion has not been reported to be particularly relevant at such low material temperatures, but the presence of Zn and Pb compounds in the deposits have been found to induce corrosion already in the 300 deg C - 400 deg C temperature range. Upon combustion, Zn and Pb may react with Cl and S to form chlorides and sulphates in the flue gases. These specific heavy metal compounds are of special concern due to the formation of low melting salt mixtures. These low melting, gaseous or solid compounds are entrained in the flue gases and may stick or condense on colder surfaces of furnace walls and superheaters when passing the convective parts of the boiler, thereby forming an aggressive deposit. A deposit rich in heavy metal (Zn, Pb) chlorides and sulphates increases the risk for corrosion which can be additionally enhanced by the presence of a molten phase. The objective of this study was to obtain better insight into high-temperature corrosion induced by Zn and Pb and to estimate the behaviour and resistance of some boiler superheater and waterwall materials in environments rich in those heavy metals

  19. 锅炉小径管焊缝超声波探伤%Boiler Tube Weld Ultrasonic Inspection Trails

    Institute of Scientific and Technical Information of China (English)

    侯耀民

    2014-01-01

    The main trail for boiler tube weld ultrasonic testing to start discussion outlines the instruments and test blocks used in testing and systematic analysis of the test methods and T91 trails pipe weld ultrasonic inspection process, in order to provide reference for detection work .%主要针对锅炉小径管焊缝超声波探伤展开探讨,简述了探伤所用的仪器和试块,并系统分析了检验方法和 T91小径管焊缝超声探伤过程,以期能为检测工作提供参考和借鉴。

  20. Pressure tests to assess the significance of defects in boiler and superheater tubing

    International Nuclear Information System (INIS)

    Internal pressure tests on 9 per cent Cr-1 per cent Mo steel tubing containing artificial defects demonstrated that the resultant loss of strength was less than a simple calculation based on the reduced tube thickness would suggest. Bursting tests on tubes containing longitudinal defects of varying length, depth and acuity showed notch strengthening at ambient temperature and at 5500C. A flow stress concept developed for simple bursting tests was shown to apply to creep conditions at 5500C. Results of creep and short-term bursting tests show that the length as well as the depth of the defect is an important factor affecting the life of bursting strength of the tubes. Defects less than 10 per cent of the tube thickness were found to have an insignificant effect. (author)

  1. A thin-lip rupture of carbon steel superheater boiler tube

    International Nuclear Information System (INIS)

    A ruptured A 42 medium carbon steel tube was collected by the engineering department in one of our steam power stations. Inspection of ruptured tube revealed a thin - lip fracture with brownish thin layer of oxide film on inner tube surfaces. There was no evidence of pitting, the outer surfaces of the tube exhibited a general oxidized conditions. A micro section taken near the fracture surface consists of ferrite and martensite, the amount of martensite decreased as we away from the fracture surface. Presence of martensite phase in the microstructure indicates that the tube material has been overheated. An erosion corrosion mechanism in conjunction with overheated. An erosion corrosion mechanism in conjunction with overheating resulted in strength deterioration with consequent premature failure. 4 fig., 1 tab

  2. Specific features of flash welding of thin-walled boiler tubes

    International Nuclear Information System (INIS)

    The possibility of flash welding of pipes from Kh18N12T steel with walls less than 4 mm thick was investigated. The structure of welds was studied with the aid of X-ray and electron microscopy methods. The results of the work was the development of a procedure for flash welding boiler pipes 32 mm in diameter and with 2 mm thick walls. There is observed a partial burning out of titanium in the welded joint, the content of other alloying elements remaining unchanged. The contact resistance of the cross section being welded is usable for a programmed control of the welding process

  3. Reproducibility of results of ultrasonic testing of welded joints of boiler heating surface tubes

    International Nuclear Information System (INIS)

    Reproducibility of the results of the ultrasonic inspection of welded joints of the heating surfaces of boilers depends substantially on the extent of differences between the frequency characteristics of selectors of the same type and on the spectrum of a probing signal. To assure the reproducibility and reliability of the results of the ultrasonic testing of the above joints it is necessary to ascertain the probing signal spectrum as the main parameter of the ultrasonic defectoscopy, and to standardize spectral characteristics of the selectors. The checking of the latter is carried out by means of a spectrum analyzer

  4. Long-term creep rupture strength of weldment of Fe-Ni based alloy as candidate tube and pipe for advanced USC boilers

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Gang; Sato, Takashi [Babcok-Hitachi K.K., Hiroshima (Japan). Kure Research Laboratory; Marumoto, Yoshihide [Babcok-Hitachi K.K., Hiroshima (Japan). Kure Div.

    2010-07-01

    A lot of works have been going to develop 700C USC power plant in Europe and Japan. High strength Ni based alloys such as Alloy 617, Alloy 740 and Alloy 263 were the candidates for boiler tube and pipe in Europe, and Fe-Ni based alloy HR6W (45Ni-24Fe-23Cr-7W-Ti) is also a candidate for tube and pipe in Japan. One of the Key issues to achieve 700 C boilers is the welding process of these alloys. Authors investigated the weldability and the long-term creep rupture strength of HR6W tube. The weldments were investigated metallurgically to find proper welding procedure and creep rupture tests are ongoing exceed 38,000 hours. The long-term creep rupture strengths of the HST weld joints are similar to those of parent metals and integrity of the weldments was confirmed based on with other mechanical testing results. (orig.)

  5. Substantiation of causes for damage of water-wall tubes of an external salt compartment of a high-pressure boiler

    Science.gov (United States)

    Fedorov, A. I.

    2014-10-01

    The damageability for water-wall tubes of an external salt compartment of a TPE-208 boiler is analyzed. The general cause for tube damage is the intensive underslime corrosion of the inner surface, which is caused by a local increase in the salt concentration in boiler water. The experiment-calculated method showed that continuous bleeding from an external cyclone being the first in water downstream causes a substantial increase in the concentration of salts (more than by a factor of three) and scale-forming agents within a contour of the loop of a distant cyclone in comparison with the variant of bleeding from a loop being the second in water downstream.

  6. Combustion monitoring of a water tube boiler using a discriminant radial basis network.

    Science.gov (United States)

    Sujatha, K; Pappa, N

    2011-01-01

    This research work includes a combination of Fisher's linear discriminant (FLD) analysis and a radial basis network (RBN) for monitoring the combustion conditions for a coal fired boiler so as to allow control of the air/fuel ratio. For this, two-dimensional flame images are required, which were captured with a CCD camera; the features of the images-average intensity, area, brightness and orientation etc of the flame-are extracted after preprocessing the images. The FLD is applied to reduce the n-dimensional feature size to a two-dimensional feature size for faster learning of the RBN. Also, three classes of images corresponding to different burning conditions of the flames have been extracted from continuous video processing. In this, the corresponding temperatures, and the carbon monoxide (CO) emissions and those of other flue gases have been obtained through measurement. Further, the training and testing of Fisher's linear discriminant radial basis network (FLDRBN), with the data collected, have been carried out and the performance of the algorithms is presented. PMID:20864104

  7. A Numerical Model Prediction for Boiling Multi Channel Flow Rate Distribution and Application in 600MW Supercritical Variable-Pressure Once-Through Boiler with Vertical Tube Coils

    Institute of Scientific and Technical Information of China (English)

    1996-01-01

    Flow rate distribution is important in a multi channel system when the flow is heated non-uniformly,This paper describes a steady state approach for obtaining the flow distribution among various tubes of complex multi channel system,Based on the Present approach,a program has been developed which is directly applied in thermal hydraulic design and investigation of 600MW supercritical variable-pressure once through boiler.

  8. Evaluation of Thermocyclic Oxidation Behavior of HVOF-Sprayed NiCrFeSiB Coatings on Boiler Tube Steels

    Science.gov (United States)

    Ramesh, M. R.; Prakash, S.; Nath, S. K.; Sapra, Pawan Kumar; Krishnamurthy, N.

    2011-09-01

    High velocity oxy-fuel (HVOF) spray process has grown into a well-accepted industrial technology for obtaining coatings resistant to significant surface degradation processes. In the present study, HVOF process was used to deposit Ni-based hardfacing NiCrFeSiB alloy powder on kinds of boiler tube steels designated as SA210 grade-A1, SA213-T11, and SA213-T22. The microstructures and several properties of the as-sprayed coatings have been investigated. Thermocyclic oxidation studies were performed in static air at 900 °C. NiCrFeSiB-coated steels showed slow oxidation kinetics and considerably lower weight gains than that of uncoated steels. The superior performance of NiCrFeSiB coatings can be attributed to continuous and protective thin oxide scale of amorphous SiO2 and Cr2O3 formed on the surface of the oxidized coatings. The combined technique of x-ray diffraction, scanning electron microscopy, energy dispersive x-ray analysis, and electron probe microanalysis are used to characterize reaction products of the oxidized surfaces.

  9. Hot Corrosion Studies of HVOF-Sprayed Coating on T-91 Boiler Tube Steel at Different Operating Temperatures

    Science.gov (United States)

    Bhatia, Rakesh; Singh, Hazoor; Sidhu, Buta Singh

    2013-11-01

    The aim of the present work is to investigate the usefulness of high velocity oxy fuel-sprayed 75% Cr3C2-25% (Ni-20Cr) coating to control hot corrosion of T-91 boiler tube steel at different operating temperatures viz 550, 700, and 850 °C. The deposited coatings on the substrates exhibit nearly uniform, adherent and dense microstructure with porosity less than 2%. Thermogravimetry technique is used to study the high temperature hot corrosion behavior of uncoated and coated samples. The corrosion products of the coating on the substrate are analyzed by using XRD, SEM, and FE-SEM/EDAX to reveal their microstructural and compositional features for the corrosion mechanisms. It is found that the coated specimens have shown minimum weight gain at all the operating temperatures when compared with uncoated T-91 samples. Hence, coating is effective in decreasing the corrosion rate in the given molten salt environment. Oxides and spinels of nickel-chromium may be the reason for successful resistance against hot corrosion.

  10. The effect of alternative amines on the rate of boiler tube fouling

    Energy Technology Data Exchange (ETDEWEB)

    Turner, C.W.; Klimas, S.J.; Brideau, M.G

    1997-10-01

    Rates for the deposition of magnetite and hematite particles onto Alloy 600 surfaces, and for magnetite particles depositing onto surfaces prefouled with sintered porous magnetite deposits were measured. The measurements were made in a high-temperature loop, under typical steam generator operating conditions, with pH controlled using morpholine, ethanolamine, ammonia, dimethylamine, or potassium hydroxide. Deposition rates were compared as a function of the nature of the particle, tube surface morphology, and the reagent used for pH control for steam qualities ranging up to 50%. Conclusions drawn from this work are: the particle deposition rate of hematite is about an order of magnitude greater than the rate for magnetite on bare Inconel 600 surfaces; the nature of the amine used for pH control affects the magnetite deposition rate. The lowest deposition rate for magnetite is obtained when dimethylamine is used for pH control; the deposition rate of magnetite increases with increasing concentration of amine (at constant pH); under reducing conditions with no detectable oxygen and with free hydrazine, the deposition rate of hematite decreases towards the value for magnetite; the particle deposition rate can be affected by the tube surface morphology; the deposition rate is significantly higher on surfaces covered with porous deposits; the heat transfer mechanism and steam quality strongly affect the deposition rate. The deposition rate increases abruptly at high steam qualities; and here is no evidence that the volatility of the amine affects the deposition behaviour. (author)

  11. The effect of alternative amines on the rate of boiler tube fouling

    International Nuclear Information System (INIS)

    Rates for the deposition of magnetite and hematite particles onto Alloy 600 surfaces, and for magnetite particles depositing onto surfaces prefouled with sintered porous magnetite deposits were measured. The measurements were made in a high-temperature loop, under typical steam generator operating conditions, with pH controlled using morpholine, ethanolamine, ammonia, dimethylamine, or potassium hydroxide. Deposition rates were compared as a function of the nature of the particle, tube surface morphology, and the reagent used for pH control for steam qualities ranging up to 50%. Conclusions drawn from this work are: the particle deposition rate of hematite is about an order of magnitude greater than the rate for magnetite on bare Inconel 600 surfaces; the nature of the amine used for pH control affects the magnetite deposition rate. The lowest deposition rate for magnetite is obtained when dimethylamine is used for pH control; the deposition rate of magnetite increases with increasing concentration of amine (at constant pH); under reducing conditions with no detectable oxygen and with free hydrazine, the deposition rate of hematite decreases towards the value for magnetite; the particle deposition rate can be affected by the tube surface morphology; the deposition rate is significantly higher on surfaces covered with porous deposits; the heat transfer mechanism and steam quality strongly affect the deposition rate. The deposition rate increases abruptly at high steam qualities; and here is no evidence that the volatility of the amine affects the deposition behaviour. (author)

  12. Inelastic behaviour of solar boiler tubes subjected to cyclic thermal loading

    International Nuclear Information System (INIS)

    Relying upon three-dimensional results previously obtained in the elastic range, we propose a simplified theory according to which each fiber of the tube portion undergoes either an uniaxial stress state (taking into account plastic flow with linear isotropic strain-hardening, possibly with creep) or a plane stress state in order to account for the ratchet phenomenon due to the inner fluid pressure. This approach allows to display and individualize the respective roles of strain-hardening, creep, fluid pressure and end-conditions; it also permits to calculate (most often in closed form) the deformations and stresses after a large number of cycles, which is not possible with more refined theories. Its accuracy has been assessed by computing the stresses and strains in the same situations for the first cycle by using an elasto-plastic shell theory (also taking into account creep influence), which revealed that in most cases our approach could give a good understanding of the phenomenon as well as a simple tool for actually calculating the mechanical quantities after a large number of cycles, in order to estimate the structure life-time. (orig./HP)

  13. Thermo-hydraulic characteristics of serpentine tubing in the boilers of gas cooled reactors under condition of rapid and slow depressurization

    International Nuclear Information System (INIS)

    In nuclear reactors of the magnox or advanced gas cooled type, serpentine tubing is used in some designs to generate steam in a once through arrangement. The calculation of accidents using two phase flow codes requires knowledge of the heat transfer behaviour of the boiler steam side. A series of experiments to study the blowdown characteristics of a typical serpentine boiler section was devised in order to validate the MARTHA section of the MACE code used by nuclear electric . The tests were carried out on the thermal hydraulics experimental research assembly (THERA) loop at manchester university. Depressurization from an initial pressure of 60 bar, with fluid subcooling of 5 k, 50 k, and 100 k was controlled by discharging the test section contents through suitably chosen orifices to produce blowdown to 10% of the initial pressure over a time scale of 30 s to 3600 s. pressures and temperatures in the serpentine were measured at average time intervals of approximately 1 s

  14. 对某锅炉前后管板裂纹及爆管的事故分析与处理%Accident Analysis and Processing of Front and Back Tube Plate Cracking and Tube Explosion of a Boiler

    Institute of Scientific and Technical Information of China (English)

    藏秀君

    2014-01-01

    为了确保锅炉水处理检验工作质量,防止和减少由于结垢、腐蚀及蒸汽质量恶化而造成的事故,促进锅炉运行的安全、经济、节能、环保,本文对吉林某航空院校锅炉,在使用运行过程中没有建立建全水处理管理、岗位职责、运行操作、维护保养等制度及化验员检验指标不真实的状况进行分析。经笔者监督检测了锅炉给水的硬度YD=6.5mmol/L,溶解固形物5000mg/L,锅水碱度、悬浮物严重超标,及其它指标均不符合标准。该校锅炉化验员没有认真执行GB/T1576-2008《工业锅炉水质》标准要求,造成锅炉严重结垢、腐蚀爆管等事故,经分析,提出解决及处理方案。%In order to ensure the quality of water treatment of boiler inspection, prevent and reduce the accident due to fouling, corrosion and steam quality deterioration, and promote safety, economy, energy saving, environmental protection of boiler operation, this paper analyzes the situation of without building the complete water treatment management, job responsibilities, operation, and maintenance system and unreal lab technician test index in the operation process of the boiler in a Jilin aviation college. The supervision and inspection of the boiler feed water hardness, YD=6.5mmol/L, dissolved solids 5000mg/L, suspended boiler water alkalinity seriously exceeds the standard, and other indicators do not meet the standard. The school boiler technicians do not seriously implement the requirements of standard GB/T1576-2008"quality"of industrial boiler, which causes the accidents of serious scaling and corrosion of boiler tube explosion. After analysis, this paper proposes the solutions and the treatment schemes.

  15. Development of high strength and high corrosion resistance 23Cr-18Ni-3Cu-1.5W steel tubes for boilers; Boiler yo kokyodo kotaishoku 23Cr-18Ni-3Cu-1.5W kokan no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Senba, H.; Sawaragi, Y.; Yamadera, Y.; Igarashi, M. [Sumitomo Metal Industries, Ltd., Osaka (Japan)

    1998-06-15

    An austenitic steel 23Cr-18Ni-3Cu-1.5W-0.4Nb-0.2N tube (SAVE25) is developed, high in strength and corrosion resistance, intended for use singly under the ultimate steam conditions (650degC and 350atm) for ultra supercritical power plants. This steel exhibits a high creep rupture strength, thanks to precipitation strengthened by a Cu-rich phase and carbon nitrides and to solid solution strengthened by texture-stabilizing W and N, and exhibits an estimated rupture strength of 91MPa after 10{sup 5}h at 700degC, equivalent to that of the high-Ni, high-W alloy HR6W (23Cr-43Ni-6W-Ti, Nb). Furthermore, its steam oxidation resistance and high-temperature corrosion resistance are so high as to be comparable to those of the HR3C (25Cr-20Ni-0.4Nb-0.25N). As for weldability, the SAVE25 is equal or superior to the TP347H which is widely used for boilers. New welding consumables are also under development, using the same alloy as the parent alloy, which produce welded joints which are equal to the parent alloy in terms of strength and corrosion resistance. This steel tube is already installed on service boilers for performance evaluation, and it is believed that the new steel tube will greatly contribute to the embodiment of ultra supercritical power plants. 11 refs., 19 figs., 2 tabs.

  16. Extensive feedwater quality control and monitoring concept for preventing chemistry-related failures of boiler tubes in a subcritical thermal power plant

    International Nuclear Information System (INIS)

    Prevention and minimizing corrosion processes on steam generating equipment is highly important in the thermal power industry. The maintenance of feedwater quality at a level corresponding to the standards of technological designing, followed by timely respond to the fluctuation of measured parameters, has a decisive role in corrosion prevention. In this study, the comprehensive chemical control of feedwater quality in 210 MW Thermal Power Plant (TPP) was carried out in order to evaluate its potentiality to assure reliable function of the boiler and discover possible irregularity that might be responsible for frequent boiler tube failures. Sensitive on-line and off-line analytical instruments were used for measuring key and diagnostic parameters considered to be crucial for boiler safety and performances. Obtained results provided evidences for exceeded levels of oxygen, silica, sodium, chloride, sulfate, copper, and conductivity what distinctly demonstrated necessity of feedwater control improvement. Consequently, more effective feedwater quality monitoring concept was recommended. In this paper, the explanation of presumable root causes of corrosive contaminants was given including basic directions for their maintenance in proscribed limits. -- Highlights: • Feedwater quality monitoring practice in a thermal power plant has been evaluated. • The more efficient feedwater quality control have been applied. • Analysis of feedwater quality parameters has been performed. • Exceeded levels of corrosive contaminants were found. • Recommendations for their maintenance at proscribed values were given

  17. A Study of the Effect of Kaolin as a Fuel Oil Additive on the Corrosion Inhibition of Fireside Superheater Boiler Tubes

    Directory of Open Access Journals (Sweden)

    Alaa' Mshjel Ali

    2010-01-01

    Full Text Available The objective of the present study is to determine the effect of Kaolin as a fuel oil additive to minimize the fireside corrosion of superheater boiler tubes of ASTM designation (A213-T22 by increasing the melting point of the formed slag on the outside tubes surface, through the formation of new compounds with protective properties to the metal surface. The study included measuring corrosion rates at different temperatures with and without additive use with various periods of time, through crucible test method and weight loss technique.A mathematical model represents the relation between corrosion rate and the studied variables, is obtained using statistical regression analysis. Using this model, the best additive to ash weight ratio was specified. Then scanning electron microscopic images taken to the two treated and untreated samples with additive to study the difference in nature of slag formed on the metal surface to the two cases.

  18. MODELLING, SIMULATING AND OPTIMIZING BOILERS

    DEFF Research Database (Denmark)

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

    to operate a boiler plant dynamically means that the boiler designs must be able to absorb any fluctuations in water level and temperature gradients resulting from the pressure change in the boiler. On the one hand a large water-/steam space may be required, i.e. to build the boiler as big as......This paper describes the modelling, simulating and optimizing including experimental verification as being carried out as part of a Ph.D. project being written resp. supervised by the authors. The work covers dynamic performance of both water-tube boilers and fire tube boilers. A detailed dynamic...... model of the boiler has been developed and simulations carried out by means of the Matlab integration routines. The model is prepared as a dynamic model consisting of both ordinary differential equations and algebraic equations, together formulated as a Differential-Algebraic-Equation system. Being able...

  19. MODELLING, SIMULATING AND OPTIMIZING BOILERS

    DEFF Research Database (Denmark)

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

    This paper describes the modelling, simulating and optimizing including experimental verification as being carried out as part of a Ph.D. project being written resp. supervised by the authors. The work covers dynamic performance of both water-tube boilers and fire tube boilers. A detailed dynamic...... model of the boiler has been developed and simulations carried out by means of the Matlab integration routines. The model is prepared as a dynamic model consisting of both ordinary differential equations and algebraic equations, together formulated as a Differential-Algebraic-Equation system. Being able...... to operate a boiler plant dynamically means that the boiler designs must be able to absorb any fluctuations in water level and temperature gradients resulting from the pressure change in the boiler. On the one hand a large water-/steam space may be required, i.e. to build the boiler as big as...

  20. Modelling, simulating and optimizing Boilers

    DEFF Research Database (Denmark)

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

    2003-01-01

    This paper describes the modelling, simulating and optimizing including experimental verication as being carried out as part of a Ph.D. project being written resp. supervised by the authors. The work covers dynamic performance of both water-tube boilers and re tube boilers. A detailed dynamic model...... of the boiler has been developed and simulations carried out by means of the Matlab integration routines. The model is prepared as a dynamic model consisting of both ordinary differential equations and algebraic equations, together formulated as a Differential-Algebraic- Equation system. Being able...... to operate a boiler plant dynamically means that the boiler designs must be able to absorb any uctuations in water level and temperature gradients resulting from the pressure change in the boiler. On the one hand a large water-/steam space may be required, i.e. to build the boiler as big as possible...

  1. 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...

  2. Failure Analysis of Platen Superheater Tube of Fuel-oil Boiler%炼厂燃油锅炉屏式过热器管失效分析

    Institute of Scientific and Technical Information of China (English)

    莫烨强; 罗建成; 孙亮; 侯艳宏

    2014-01-01

    采用宏观观察、金相观察、扫描电子显微分析、成分分析等分析方法,对燃油锅炉屏式过热器发生开裂失效原因进行了分析研究。结果表明:该管长期在高温下运行产生了蠕变现象;珠光体组织出现严重的球化现象,大量碳化物呈链状沿晶界析出;过热器管道内壁存在约371.55μm厚度的氧化层。因此,管束长期局部过热服役,致使金相组织发生改变,大大降低了材料的力学性能,从而发生蠕变开裂现象。%The failure reasons of a platen superheater tube of a fuel-oil boiler were studied by macroscopic observation, metallographic analysis, scanning electron microscopy ( SEM ) and energy dispersive spectroscopy ( EDS ) . The result of macroscopic observation shows that creep cracking happened to the tube after working for a long time at high temperature. The result of metallographic analysis shows that the carbide precipitated at grain boundaries. The result of scanning electron microscopy( SEM) and energy dispersive spectroscopy( EDS) show that a oxidation layer formed on the inside of the tube. The thickness of the oxidation layer was 371. 55μm. It can be concluded that long-term local overheating occurred to the tube during working, leading to microstructure change and reducing the mechanical properties of the material.

  3. Discussion and Analysis of the Causes of Accident of Steam Boiler Tube Rupture and the Processing Methods%蒸汽锅炉爆管事故原因及处理方法探讨分析

    Institute of Scientific and Technical Information of China (English)

    李伟忠; 安文广; 张丽波

    2012-01-01

    蒸汽锅炉在运行过程中,一旦发生爆管事故,会损坏邻近的管壁,冲塌炉墙,并且在很短的时间造成锅炉严重缺水,使事故扩大,因此须保证安全可靠,确保安全生产运行.本文主要探讨蒸汽锅炉运行中锅炉爆管事故原因及处理方法.%Once the accident of tube rupture for steam boiler during operation happened, it can damage the nearby tube wall, and collapse furnace wall, resulting in serious water shortages for boiler in a very short period of time, expanding the accident, therefore, we must ensure the safety and reliability, safe production and operation. This paper mainly discusses the causes and treatment methods of accident of boiler tube rupture in the operation of steam boiler.

  4. Degradation behavior of Ni{sub 3}Al plasma-sprayed boiler tube steels in an energy generation system

    Energy Technology Data Exchange (ETDEWEB)

    Sidhu, B.S.; Prakash, S. [GZS, Bathinda (India). College of Engineering

    2005-06-01

    Boiler steels, namely, low-C steel, ASTM-SA210-Grade A1 (GrA1), 1Cr-0.5Mo steel, ASTM-SA213-T-11 (T11) and 2.25Cr-1Mo steel, ASTM-SA213-T-22 (T22) were plasma sprayed with Ni3Al. The alloy powder was prepared by mixing Ni and Al in the stoichiometric ratio of 3 to 1. The Ni-22Cr-10Al-1Y alloy powder was used as a bond coat, with a 150{mu} m thick layer sprayed onto the surface before applying the 200{mu}m coating of Ni{sub 3}Al. Exposure studies have been performed in the platen superheater zone of a coal-fired boiler at around 755{sup o}C for 10 cycles, each of 100 h duration. The protection to the base steel was minimal for the three steels. Scale spallation and the formation of a porous and nonadherent NiO scale were probably the main reasons for the lack of protection. In the case of T22-coated steel, cracks in the coatings have been observed after the first 100 h exposure cycle.

  5. Degradation behavior of Ni3Al plasma-sprayed boiler tube steels in an energy generation system

    Science.gov (United States)

    Sidhu, Buta Singh; Prakash, S.

    2005-06-01

    Boiler steels, namely, low-C steel, ASTM-SA210-Grade A1 (GrA1), 1Cr-0.5Mo steel, ASTM-SA213-T-11 (T11) and 2.25Cr-1Mo steel, ASTM-SA213-T-22 (T22) were plasma sprayed with Ni3Al. The alloy powder was prepared by mixing Ni and Al in the stoichiometric ratio of 3 to 1. The Ni-22Cr-10Al-1Y alloy powder was used as a bond coat, with a 150 µm thick layer sprayed onto the surface before applying the 200 µm coating of Ni3Al. Exposure studies have been performed in the platen superheater zone of a coal-fired boiler at around 755 °C for 10 cycles, each of 100 h duration. The protection to the base steel was minimal for the three steels. Scale spallation and the formation of a porous and nonadherent NiO scale were probably the main reasons for the lack of protection. In the case of T22-coated steel, cracks in the coatings have been observed after the first 100 h exposure cycle.

  6. Conduction cooled tube supports

    Science.gov (United States)

    Worley, Arthur C.; Becht, IV, Charles

    1984-01-01

    In boilers, process tubes are suspended by means of support studs that are in thermal contact with and attached to the metal roof casing of the boiler and the upper bend portions of the process tubes. The support studs are sufficiently short that when the boiler is in use, the support studs are cooled by conduction of heat to the process tubes and the roof casing thereby maintaining the temperature of the stud so that it does not exceed 1400.degree. F.

  7. Hot Corrosion Behaviour of Type 316 Stainless Steel Tubes used in Reheaters and Superheaters of Oil-Fired Boilers

    International Nuclear Information System (INIS)

    High temperature corrosion behaviour of commercial type 316 stainless steel tubes has been studied in the presence of Na2 SO4 and NaCl at temperature ranged from 500 to 800 degree C. Tubes of different diameters ranging from 8 to 25 mm and thickness ranging from 1.9 to 4.3 mm were used in the study. The aggressive environment was 1 N Na2 SO4 + 1 N NaCl and vanadium compound was added as ammonium meta vanadate in some tests. corrosion kinetics based on weight change vs. Time measurements and microstructural analysis were used to determine the mode of corrosion attack and nature of the formed scales. As a result of the study it was found that the spilling increases as the temperature increases and led to weight loss, also the addition of vanadium to the solution caused a sharp increase in weight i.e. high corrosion rate, for all diameters. 11 Figs

  8. Cracking and corrosion recovery boiler

    Energy Technology Data Exchange (ETDEWEB)

    Suik, H. [Tallinn Technical University, Horizon Pulp and Paper, Tallinn (Estonia)

    1998-12-31

    The corrosion of heat surfaces and the cracking the drums are the main problems of the recovery boiler. These phenomena have been appeared during long-term operation of boiler `Mitsubishi - 315` erected at 1964. Depth of the crack is depending on the number of shutdowns and on operation time. Corrosion intensity of different heat surfaces is varying depend on the metal temperature and the conditions at place of positioning of tube. The lowest intensity of corrosion is on the bank tubes and the greatest is on the tubes of the second stage superheater and on the tubes at the openings of air ports. (orig.) 5 refs.

  9. Boiler Retrofit for the Utilization of Biodiesel

    OpenAIRE

    Leily Nurul Komariah; Marwani Marwani

    2016-01-01

    Fuel oil used in the boiler is able to substitute with biodiesel. In lower blends, there are no engine modification needed, but some researchers recommended some technical adjustments in order to maintain the boiler's performance and equipment durability. This study consists of the comparison between the performance of boiler before and after retrofitting on the use of biodiesel. The diesel oil was introduced in biodiesel blends of 10% (B10), 20% (B20) and 25% (B25). A fire tube boiler was us...

  10. 超超临界电站锅炉小径管焊缝超声波探伤%Ultrasonic Testing of the Welds of Small Caliber Tube in the Ultra Supercritical Power Station Boiler

    Institute of Scientific and Technical Information of China (English)

    朱健

    2011-01-01

    对T91材质的电站锅炉小径管焊缝进行了超声波检测,使用常规探头以及试块来调节扫描声速.%The ultrasonic testing was done to the welds of small caliber tube of T91 material in the power station boiler, and the scan speed was adapted by normal probe.

  11. High temperature properties of the seam weld portion in 1% Cr-0.5% Mo ERW boiler tubing after long-term aging

    International Nuclear Information System (INIS)

    This study is aimed at the evaluation of reliability of the seam weld portion of 1% Cr-0.5% Mo ERW (Electric Resistance Welding) boiler tubings for high temperature use. High temperature properties of materials aged in the temperature between 500 and 6000C for 5000 h were evaluated by a slow extension rate test (SERT) and a low cycle fatigue test at high temperatures. Microscopic observation was also made with a scanning electron microscope and a transmission electron microscope. Proof stress and tensile strength obtained by SERT tend to decrease with an increase in aging temperature. It is confirmed that the strength of the seam weld portion is higher than that of the base metal. The fatigue crack propagation rates studied by test pieces with a side-notch either at the base metal or at the seam weld portion were found to be lower at the seam weld portion compared with that at the base metal. Dislocations of high density and fine precipitates of carbides were observed with electron microscopy in the seam weld portion. It is also found that the size of dislocation cells formed during fatigue is smaller in the seam weld portion than in the base metal. It is concluded that higher strength of the seam weld portion is closely related to the above mentioned microstructure originated in the dissolution of carbides during ERW process. 10 figures, 3 tables

  12. Rupture Causes Analysis and Countermeasures on Rear Platen Superheater Tube of 300 MW Power Station Boiler%300MW电站锅炉后屏过热器爆管原因分析和对策

    Institute of Scientific and Technical Information of China (English)

    黎小秋; 赵康文; 唐囡; 何可龙

    2012-01-01

    Based on the experimental data, an failure analysis about the causes of the dissimilar steel weld joints rupture in the rear platen superheater tube of a large power plant boiler has been done. The results demonstrated that the enriched carbon layers around the melting line, residual stress and stress concentration leads to a premature failure of the dissimilar steel weld joints, and the retrofitting measures are introduced to ensure the safe operation of the power station boiler. At the same time, it can also supply references to the failure analysis of the similar structure boiler heating tubes.%在试验的基础上,对某大型电站锅炉后屏过热器管异种钢焊缝破裂的原因进行了失效分析,结果表明熔合线增碳层,残余应力和应力集中导致了异种钢焊缝的早期失效,并提出了相应的改进措施以确保电站锅炉安全运行,同时,也可为同类型结构锅炉受热面管的失效分析提供参考.

  13. 85 T/H 锅炉低温过热器爆管原因分析与总结%ANALYSIS AND SUMMARY ON TUBE RUPTURE IN THE LOW TEMPERATURE SUPERHEATER OF 85 T/H BOILER

    Institute of Scientific and Technical Information of China (English)

    任燕军

    2014-01-01

    This paper analyzes the cause of tube rupture in the low temperature superheater of 85t/h boiler in the company , tries to find out the reasons and point out the settlement method in order to provide reference for boiler maintenance work in the future .%文章对广州钢铁控股有限公司85t/h锅炉一级过热器管爆管的原因进行了分析,找出原因,并提出了相应的解决措施,以求对今后的锅炉检修维护工作有所借鉴。

  14. Biomass boilers

    OpenAIRE

    Nahodil, Jiří

    2011-01-01

    Bachelor’s thesis deals with the use of biomass for heating houses and apartment houses. The first part is dedicated to biomass. Here are mentioned the possibility of energy recovery, treatment and transformation of biomass into a form suitable for burning, its properties and combustion process itself. The second part is devoted to biomass boilers, their separation and description. The last section compares the specific biomass boiler with a boiler to natural gas, particularly from an economi...

  15. 生物质燃料锅炉20G钢低温过热器管爆裂失效分析%Burst failure analysis on 20G steel low temperature superheater tube of biomass-fired boiler

    Institute of Scientific and Technical Information of China (English)

    卿辉; 任耀剑; 孙智

    2014-01-01

    Reason for the failure of low temperature superheater tube of biomass-fired boiler during working was analyzed .The results show that the tube burst is related to the ash of biomass fuel and many short-terms over-high temperature .The alkali chloride and sulfide of the ash of biomass fuel accelerated corrosion and oxides generated , and the tube undergone short-term over-temperature repeatedly .Over-temperature caused pearlitic spheroidization and decreased strength of the material in the meantime .The tube cracking was due to the tube wall thinned by oxide abscission , and could not resist the boiler pressure .%某生物质燃料锅炉低温过热器管在运行中爆裂,对其失效原因进行了分析。结果表明,爆管的原因与生物质燃料灰分和多次短时超温有关。燃料灰分中的碱金属氯化物、硫化物使腐蚀加速,形成氧化物的速度加快,并使管道经历多次短时超温。超温造成组织中珠光体球化,使材料强度下降。氧化物脱落后,管壁的实际壁厚减薄,不足以承受管中的压力导致爆裂。

  16. Power for the industrial age: a brief history of boilers

    Energy Technology Data Exchange (ETDEWEB)

    Kuehn, S.E.

    1996-02-01

    Boilers were first designed in Greece during the Hellenistic period by Hero, but they were regarded purely as a novelty and no industrial application was found for these toys until the seventeenth century when mining engineers used them for steam-powered pumps. By the end of the 17th century the early shell boilers were replaced by tube boilers, the direct ancestors of the modern boiler. Among the best known of the early boiler manufacturers was Babcock and Wilcox, and they supplied boilers to one of the first electric power plants. In the early 20th century superheaters, economizers, stokers and pulverizers were added to the design of the utility boiler. Fusion-welded boiler drums added to safety. More recently environmental concerns have initiated a new generation of boilers, such as the pressurised fluidised bed combustion boilers and their advanced versions. 5 refs., 3 figs.

  17. 油田热电厂注汽锅炉炉管腐蚀因素分析与控制措施%Corrosion Factors Analysis and Control Measures of Boiler Tubes in Steam In?jection Boiler in the Oilfield

    Institute of Scientific and Technical Information of China (English)

    周登印

    2016-01-01

    The steam injection boiler furnace tube of Daqing oilfield thermal power plant is in high temperature, high pressure and other harsh environmental conditions. The corrosion types are mainly alkali corrosion,dissolved oxygen corrosion,cavitation erosion,steam wa-ter corrosion and stop furnace corrosion. The corrosion factors produced by the medium mainly include temperature, flow rate and water treatment quality. The dissolved oxygen in the oxygen, and the boiler water in the steam injection boiler furnace, that have accelerated the corrosion rate of the furnace tubes. On the basis of corrosion factors targeted research, from the control of boiler feed water quality, reduce boiler oxygen exposure probability and improve the furnace pipe anti-corrosion properties of the essence, four aspects:the use of science and technology,and puts forward the corresponding control measures,aiming to de-lay and reduce the corrosion of all aspects, to prevent corrosion of the probability of more than 99.9%. By controlling the water quality of boiler and reducing the chance of contact with oxygen,the corrosion of boiler tubes is reduced.%大庆油田热电厂注汽锅炉炉管处于高温、高压的恶劣环境工况,腐蚀严重,其腐蚀类型主要为碱腐蚀、溶解氧腐蚀、气蚀、汽水腐蚀和停炉腐蚀.由介质产生的腐蚀因素主要有温度、流速及水处理质量;注汽锅炉炉管中存在的氧气以及锅炉水中溶解的氧加速了炉管腐蚀速率.为延缓腐蚀并减小腐蚀程度,提出以下对应的控制措施:严把水质源头管控,杜绝出现不达标水质进入锅炉;完善运行参数,防止超温、超压环境出现;将多种除氧方法结合使用,以达到最佳除氧效果.停炉后采用TH901法在炉管表面形成保护膜以隔离氧气,该保护法加药量少,成本低,阻止腐蚀的概率达到99.9%以上.通过控制锅炉给水水质,减少锅炉接触氧几率等措施,减缓了注汽锅炉炉管的腐蚀.

  18. 超超临界机组锅炉末级过热器爆管原因分析%Cause Analysis on Bursting of Final Superheater Tubes of a Ultra Supercritical Boiler

    Institute of Scientific and Technical Information of China (English)

    肖国华; 李益民; 王理博

    2011-01-01

    The bursting and leakage reason of final superheater T91 steel tubes of a ultra super critical boiler was analyzed through chemical compositions analysis, microstructure analysis and mechanical properties test. The results show that the failure of the final superheater tubes was due to overheat which deteriorated the microstructure and mechanical properties of the tubes material. It was believable that the overheat of the bursting tubes was caused by blockage, according to the analysis results on the spot.%通过化学成分分析、金相检验、力学性能测试等手段对某电厂超超临界锅炉末级过热器T91钢管爆裂原因进行了分析.结果表明:爆管系超温运行所致,过热导致钢管材料显微组织老化、力学性能显著下降;并根据现场情况对爆裂管的超温原因进行了分析,认为异物堵塞造成超温的可能性较大.

  19. 锅炉水冷壁管氢腐蚀爆管原因分析%Cause Analysis of Hydrogen Corrosion Induced Bursting of Waterwall Tubes in a Boiler

    Institute of Scientific and Technical Information of China (English)

    张亚明; 夏邦杰; 董爱华

    2012-01-01

    某热电厂5号锅炉水冷壁发生爆管.对取样水冷壁管进行了宏观观察、化学分析、金相分析、扫描电镜与电子能谱分析及x射线衍射分析等.结果表明,爆管原因是水冷壁管向火侧内壁局部区域发生氢腐蚀所致.提出了预防此类事故发生的措施.%Bursting failure occurred on waterwall tubes of No.5 boiler in a power plant. Macroscop- ic inspection, chemical analysis, metallurgraphy, scanning electron microscopy (SEM), energy dis-persive spectroscopy (EDS) and X-ray diffraction (XRD) were adopted to examine the failed tube. The results indicated that the tube rupture was resulted from localized hydrogen corrosion of the part facing fire. Preventive measures of such failures are put forward.

  20. 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.

  1. Computer system for monitoring power boiler operation

    Energy Technology Data Exchange (ETDEWEB)

    Taler, J.; Weglowski, B.; Zima, W.; Duda, P.; Gradziel, S.; Sobota, T.; Cebula, A.; Taler, D. [Cracow University of Technology, Krakow (Poland). Inst. for Process & Power Engineering

    2008-02-15

    The computer-based boiler performance monitoring system was developed to perform thermal-hydraulic computations of the boiler working parameters in an on-line mode. Measurements of temperatures, heat flux, pressures, mass flowrates, and gas analysis data were used to perform the heat transfer analysis in the evaporator, furnace, and convection pass. A new construction technique of heat flux tubes for determining heat flux absorbed by membrane water-walls is also presented. The current paper presents the results of heat flux measurement in coal-fired steam boilers. During changes of the boiler load, the necessary natural water circulation cannot be exceeded. A rapid increase of pressure may cause fading of the boiling process in water-wall tubes, whereas a rapid decrease of pressure leads to water boiling in all elements of the boiler's evaporator - water-wall tubes and downcomers. Both cases can cause flow stagnation in the water circulation leading to pipe cracking. Two flowmeters were assembled on central downcomers, and an investigation of natural water circulation in an OP-210 boiler was carried out. On the basis of these measurements, the maximum rates of pressure change in the boiler evaporator were determined. The on-line computation of the conditions in the combustion chamber allows for real-time determination of the heat flowrate transferred to the power boiler evaporator. Furthermore, with a quantitative indication of surface cleanliness, selective sootblowing can be directed at specific problem areas. A boiler monitoring system is also incorporated to provide details of changes in boiler efficiency and operating conditions following sootblowing, so that the effects of a particular sootblowing sequence can be analysed and optimized at a later stage.

  2. Effect of Water Quality on the Performance of Boiler in Nigerian Petroleum Industry

    OpenAIRE

    J. O. ODIGURE; A. S. ABDULKAREEM; E. T. ASUQUO

    2005-01-01

    This work investigates quality of water used in boilers of Refinery Company in Nigeria. The results shows that the quality of water fed to boilers are off specification. Low water quality used in boilers led to frequent failure of the boilers as a result of tube rupture. This has resulted into low capacity utilization and loss of processing fees. The poor performance of the boiler feed treatment plant is attributable to the deplorable condition of water intake plant, raw water treatment, demi...

  3. Smooth Surfaces: A review of current and planned smooth surface technologies for fouling resistance in boiler

    Energy Technology Data Exchange (ETDEWEB)

    Corkery, Robert; Baefver, Linda; Davidsson, Kent; Feiler, Adam

    2012-02-15

    Here we have described the basics of boilers, fuels, combustion, flue gas composition and mechanisms of deposition. We have reviewed coating technologies for boiler tubes, including their materials compositions, nano structures and performances. The surface forces in boilers, in particular those relevant to formation of unwanted deposits in boilers have also been reviewed, and some comparative calculations have been included to indicate the procedures needed for further study. Finally practical recommendations on the important considerations in minimizing deposition on boiler surfaces are made

  4. 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

  5. Experimental Study on Under-deposit Corrosion of Water Wall Tube in a 420t Utility Boiler%一台420t电站锅炉水冷壁管垢下腐蚀试验研究

    Institute of Scientific and Technical Information of China (English)

    李勇; 赵彦杰; 欧俊

    2015-01-01

    在对某电厂一台420t电站锅炉检验过程中,发现该锅炉水冷壁管存在结垢现象,水冷壁管垢下腐蚀会对锅炉的安全、经济运行造成影响。通过均匀腐蚀失效试验、氢脆腐蚀失效试验确定其腐蚀原理,并对其腐蚀速率进行了研究。%There were two under-deposit corrosion forming causes, uniform corrosion and hydrogen corrosion. In the inspection of a 420t/h utility boiler, scaling was found in its water wall tube leading to the temperature difference between different sides of water wall tube. The safety and economy will be affected. Through theory and experiment, corrosion mechanism and prevention measures were presented in this paper.

  6. Influence of Heat Flux and Friction Coefficient on Thermal Stresses in Risers of Drum Boilers under Dynamic Conditions of Steam Demand

    OpenAIRE

    M.A. Habib; Alzaharnah, I.; El-Shafei, M.; Merah, N.; Al-Anizi, S.; M. Y. Al-Awwad; Hajji, M

    2013-01-01

    Boiler swing rate, which is the rate at which the boiler load is changed, has significant influence on the parameters of the boiler operating conditions such as drum water pressure and level, steam quality in the riser tubes, wall temperatures of riser tubes, and the associated thermal stresses. In this paper, the thermal stresses developed in boiler tubes due to elevated rates of heat transfer and friction are presented versus thermal stresses developed in tubes operated under normal conditi...

  7. 超临界锅炉末级过热器爆管原因的分析%Burst Cause Analysis of Final-stage Superheater Tubes for a Supercritic al Boiler

    Institute of Scientific and Technical Information of China (English)

    赵慧传; 贾建民; 陈吉刚; 梁军; 杨红权; 尹成武

    2011-01-01

    为研究超临界锅炉末级过热器爆管的原因,对1台600MW超临界锅炉末级过热器爆管上游管和相关管样的内壁氧化物的宏观形态、微观结构,脱落氧化皮的微观结构、物相、各区域的微观形态和成分等进行了分析.结果表明:堵塞末级过热器下弯头造成过热器爆管的脱落氧化皮来自于T23/T91钢管的T23管段内壁,而非T91管段内壁;T23钢管内壁氧化皮为二层结构,外层为粗大柱状晶的纯磁铁矿(Fe3O4),内层为等轴细晶的含W和Cr的尖晶石;原生氧化皮内层存在一条或多条沿圆周方向排列的孔洞链,氧化皮容易沿孔洞链分离,从而造成氧化皮脱落.%In order to find the causes of tube burst failures encountered by the final-stage superheater of a 600 MW supercritical boiler, an analysis was carried out to both macrostructure and microstructure of the oxide scales taken from inner surface of relevant tube samples, and to the microstructure, phase, micromorphology and composition of fall-off scales. Results show that the failure has been caused by oxide scales split off from inner surface at T23 side of the T23/T91 joint, which blocked the lower elbow of the superheater and finally led to the tube burst. The scale on inner surface of T23 tube has a two-layer structure, of which the outer layer is the coarse columnar grain Fe3 O4 while the inner layer fine equiaxed spinel,containing W and Cr element. One or more hole-chains on inner surface of primitive oxide skin formed along the circumference direction are easy to break and cause the oxide skin to fall off.

  8. Steam boiler technology

    Energy Technology Data Exchange (ETDEWEB)

    Teir, S.

    2002-07-01

    The steam boiler technology e-Book is provided by the Laboratory of Energy Engineering and Environmental Protection at Helsinki University of Technology. The book covers the basics and the history of steam generation, modern boilers types and applications, steam/water circulation design, feedwater and steam systems components, heat exchangers in steam boilers, boiler calculations, thermal design of heat exchangers.

  9. Failure Analysis of Low Temperature Superheater Tube of Utility Boiler%电站锅炉低温过热器管失效分析

    Institute of Scientific and Technical Information of China (English)

    周经伟; 周荣稳

    2013-01-01

      Through making the failure analysis on low temperature superheater tube by employing the related technological means, the paper determines the cause of failure and puts preventive measures to avoid and prevent similar incidents from happening again.%  通过对低温过热器爆管,采用相关的技术手段进行失效情况分析,确定失效的原因,提出预防措施,避免和防止同类事故的再次发生。

  10. Ultrasonic Phased Array Testing for Small Diameter Tube Weld of Ultra-supercritical Boiler%超超临界锅炉小径管焊缝的超声相控阵检测工艺

    Institute of Scientific and Technical Information of China (English)

    王维东; 王亦民; 孟倩倩; 曹云峰; 张振华

    2015-01-01

    根据锅炉小径管焊缝的缺陷分布范围,研制出系列超声相控阵检测的对比试块,并进行了模拟与自然缺陷的检测试验。测试采用ϕ1 mm横孔制作距离-波幅曲线,对不同外径与壁厚的内外壁缺陷进行定量与指示长度测定,修正了传统检测的误区,建立了超声相控阵小径管焊缝的检测工艺方法。%A series of ultrasonic phased array inspection contrast test blocks were developed according to the distribution range of the boiler pipe weld defect,and at the same time tests were conducted on the simulation and natural defects,respectively.By making distance amplitude curve for 1 mm diameter horizontal hole,we quantified and measured indicating length of defects both inside and outside of the tube with different diameter and thickness, and thus corrected the errors of the traditional detection and established the testing method of ultrasonic phased array for small pipe weld.

  11. PERFORMANCE EVALUATION OF BOILERS (80 AND 40 TPH) AND 21MW STEAM TURBINE OF COGEN PLANT

    OpenAIRE

    D.P.TAWARE; P.E.CHAUDHARI; U.M.SHIRSAT

    2014-01-01

    The proposed study is conducted at The Malegaon Sugar Mills, Baramati, and District Pune. Data is collected for a high pressure 80 TPH & 40TPH bagasse fired boiler. The boilers are natural circulation and bi-drum water tube type. The both boilers are equipped with super heater, air heater and economizer in order to utilize maximum available heat of flue gases. Boiler efficiency is calculated by indirect method. Also plant has 21 MW cogeneration capacity, with two turbines are installed with c...

  12. Thermal Analysis of Superheater Platen Tubesin Boilers

    Directory of Open Access Journals (Sweden)

    Shahram Falahatkar

    2014-01-01

    Full Text Available Superheaters are among the most important components of boilers and have major importance due to this operation in high temperatures and pressures. Turbines are sensitive to the fluctuation of superheaterstemperature;therefore even the slightest fluctuation in the outlet vapor temperature from the superheaters does damage the turbine axis and fins. Examining the potential damages of combustion in the boilers and components such as the superheaters can have a vital contribution to the progression of the productivity of boiler, turbine and the power plant altogether it solutions are to be fund to improve such systems. In this study, the focus is on the nearest tube set of superheaters to the combustion chamber.These types of tubes are exposed to a wide range ofcombustion flames such that the most heat transfer to them is radiation type.Here, the 320 MW boiler of Isfahan power plant (Iran, the combustion chamber, 16 burners and the platensuperheater tubes were remodeled by CFD technique. The fluid motion, the heat transfer and combustion processes are analyzed. The two-equation turbulence model of k-εis adopted to measure the eddy viscosity. The eddy dissipation model is used to calculate the combustion as well as the P-1 radiation model to quantify the radiation. The overheated zones of superheater tubes and the combustion chamber are identified in order toimprove this problem by applying the radiation thermal shields and knees with porous crust which are introduced as the new techniques.

  13. Boiler Retrofit for the Utilization of Biodiesel

    Directory of Open Access Journals (Sweden)

    Leily Nurul Komariah

    2016-02-01

    Full Text Available Fuel oil used in the boiler is able to substitute with biodiesel. In lower blends, there are no engine modification needed, but some researchers recommended some technical adjustments in order to maintain the boiler's performance and equipment durability. This study consists of the comparison between the performance of boiler before and after retrofitting on the use of biodiesel. The diesel oil was introduced in biodiesel blends of 10% (B10, 20% (B20 and 25% (B25. A fire tube boiler was used for the test with pressure of 3 bar and heat input capacity of 60,000 kcal. The boiler retrofit is conducted by fine tuning the fan damper scale (FDS and adding a heating feature on fuel system. It was specifically intended to maintain the quality of combustion and boiler efficiency as well as to avoid an increase in fuel consumption. The combustion behaviour was monitored by exhaust emissions of CO, NOx, and SO2. The fan damper scale (FDS and fuel temperature is adjusted by the increasing portion of biodiesel used. The fuel heating apparatus was set at temperature of 40oC for the use of B10, and 60oC for B20 and B25. The FDS adjustment was successfully resulted a reduction in rate of combustion air by average of 9.2%. The boiler retrofitting for the utilization of B10, B20 and B25 showed an increase in boiler efficiency by 0.64%, 0.42% and 2.6% respectively. The boiler retrofitting is surprisingly reduced the fuel consumption by average of 11.2%.

  14. A Rule-Based Industrial Boiler Selection System

    Science.gov (United States)

    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.

    2015-09-01

    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, super heaters, air heaters and economizers. The selection of the boiler is very important to the industry for conducting the operation system successfully. The selection criteria are based on rule based expert system and multi-criteria weighted average method. The developed system consists of Knowledge Acquisition Module, Boiler Selection Module, User Interface Module and Help Module. The system capable of selecting the suitable boiler based on criteria weighted. The main benefits from using the system is to reduce the complexity in the decision making for selecting the most appropriate boiler to palm oil process plant.

  15. 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.

  16. Boilers, evaporators, and condensers

    International Nuclear Information System (INIS)

    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

  17. Central heating: package boilers

    Energy Technology Data Exchange (ETDEWEB)

    Farahan, E.

    1977-05-01

    Performance and cost data for electrical and fossil-fired package boilers currently available from manufacturers are provided. Performance characteristics investigated include: unit efficiency, rated capacity, and average expected lifetime of units. Costs are tabulated for equipment and installation of various package boilers. The information supplied in this report will simplify the process of selecting package boilers required for industrial, commercial, and residential applications.

  18. Thermo hydraulics of a steam boiler forced circulation

    International Nuclear Information System (INIS)

    In order to minimize the dryout at the steam boiler furnace in the Thermal Power Plant Kolubara B, designed are inner rifled wall tubes. This type of tubes, with many spiral grooves cut into the bore, prevents film boiling and enables the nucleate boiling be still maintained under the condition of vapour quality being app. 1. To verify the choice of the rifled tubes instead of the cheaper, smooth tubes type being justified, analyzed is the change of the actual and critical vapour quality with the furnace height, under uniform and non-uniform heat flu through evaporator walls. Furthermore, made are hydraulic calculations for various steam boiler loads, in case of both rifled and smooth tubes types, with the purpose to check the rifles influence to pressure drop increase in comparison with the smooth tubes. Also, checked is the selection of the circulation pump. Key words: evaporator, forced circulation, rifled tubes, critical vapour quality, pressure drop

  19. Model boiler studies on deposition and corrosion

    International Nuclear Information System (INIS)

    Deposit formation was studied in a model boiler, with sea-water injections to simulate the in-leakage which could occur from sea-water cooled condensers. When All Volatile Treatment (AVT) was used for chemistry control the deposits consisted of the sea-water salts and corrosion products. With sodium phosphate added to the boiler water, the deposits also contained the phosphates derived from the sea-water salts. The deposits were formed in layers of differing compositions. There was no significant corrosion of the Fe-Ni-Cr alloy boiler tube under deposits, either on the open area of the tube or in crevices. However, carbon steel that formed a crevice around the tube was corroded severely when the boiler water did not contain phosphate. The observed corrosion of carbon steel was caused by the presence of acidic, highly concentrated chloride solution produced from the sea-water within the crevice. Results of theoretical calculations of the composition of the concentrated solution are presented. (author)

  20. Analysis of Causes for Corrosion of Tube Bundle Welded Joint of Waste Heat Boiler in Ammonia Synthesis System and Improvement%氨合成系统废热锅炉管束焊接接头腐蚀原因分析及改进

    Institute of Scientific and Technical Information of China (English)

    张英杰; 韩荣芹; 左卫锋

    2013-01-01

    氨合成系统废热锅炉投运8个月后,其管束的气体进口端联箱管与换热管间的焊接接头出现连续点状腐蚀坑样缺陷,而管束的气体出口端相应位置没有出现此类缺陷,设备其他部位未见异常.通过对氨合成系统废热锅炉管束焊接接头腐蚀部位的宏观形貌、低倍形态、化学组分、扩展方向及金相组织等特征进行分析,判定腐蚀形态为电偶腐蚀.针对腐蚀形态,采取了相应的改进措施,取得了明显的效果.%8 months after putting into operation of the waste heat boiler in ammonia synthesis system,defects of continuous dotted etch pit appeared at welded joints between gas inlet connecting tube and heat exchange tube of tube bundle,while no such kind of defect found at relevant position of gas outlet of tube bundle,and there are no troubles seen in other parts of the equipment.Through analyzing features of micro profile,macroscopic appearance,chemical composition,extension direction and metallographic structure,etc.of corroded parts of the tube bundle welded joints of the waste heat boiler in ammonia synthesis system,it is determined that the corrosion form is galvanic corrosion.In connection with the corrosion form,relevant improvement measures are taken and significant effect is obtained.

  1. Effect of Water Quality on the Performance of Boiler in Nigerian Petroleum Industry

    Directory of Open Access Journals (Sweden)

    J. O. ODIGURE

    2005-06-01

    Full Text Available This work investigates quality of water used in boilers of Refinery Company in Nigeria. The results shows that the quality of water fed to boilers are off specification. Low water quality used in boilers led to frequent failure of the boilers as a result of tube rupture. This has resulted into low capacity utilization and loss of processing fees. The poor performance of the boiler feed treatment plant is attributable to the deplorable condition of water intake plant, raw water treatment, demineralization plant, change in raw water quality and non-functioning of the polisher unit.

  2. Steam boiler for fytomass

    OpenAIRE

    Baláš, Jiří

    2008-01-01

    The purpose of this Diploma Thesis was the construction design of the steam boiler for fytomass. For the specified parameters of biomass have been gradually implemented stoichiometric calculations of which are further based calculation of enthalpies of combustion gas. In the next part have been dealt with heat balance of the boiler, the efficiency of the boiler, recirculation of exhaust gases and the temperature of the combustion gases in outlet from fire. Thereinafter, the proposal of partic...

  3. 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.

  4. Evaluation of surrogate boilers for steam generators

    International Nuclear Information System (INIS)

    Steam generator damage in pressurized water reactors is a continuing problem which results from a combination of factors including mechanical design, thermal hydraulics, materials selection, fabrication techniques, water chemistry, and system design and operation. A wide variety of steam generator damage mechanisms has been identified in operating PWRs including intergranular attack, thinning, stress corrosion cracking, erosion, denting, fatigue cracking, pitting, and fretting. Model boilers operated in parallel to the steam generators, i.e., surrogate boilers, may provide a useful tool in the study of these damage mechanisms, their causative factors, and the effects of corrosion actions. To evaluate the applicability of surrogate boilers to such studies, Steam Generator Owners Group I project S111-2 was established. Evaluation of numerous surrogate boiler design alternates led to identification of several possible acceptable approaches. The appropriate surrogate feedwater was identified as plant feedwater. Capability to operate with a tube-side temperature similar to the hot-leg temperature was considered necessary as was the ability to provide mechanical, thermal, and chemical corrosion acceleration. Practical and economically feasible surrogate boiler designs were developed in response to these design requirements

  5. Super Boiler: Packed Media/Transport Membrane Boiler Development and Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Liss, William E; Cygan, David F

    2013-04-17

    Gas Technology Institute (GTI) and Cleaver-Brooks developed a new gas-fired steam generation system the Super Boiler for increased energy efficiency, reduced equipment size, and reduced emissions. The system consists of a firetube boiler with a unique staged furnace design, a two-stage burner system with engineered internal recirculation and inter-stage cooling integral to the boiler, unique convective pass design with extended internal surfaces for enhanced heat transfer, and a novel integrated heat recovery system to extract maximum energy from the flue gas. With these combined innovations, the Super Boiler technical goals were set at 94% HHV fuel efficiency, operation on natural gas with <5 ppmv NOx (referenced to 3%O2), and 50% smaller than conventional boilers of similar steam output. To demonstrate these technical goals, the project culminated in the industrial demonstration of this new high-efficiency technology on a 300 HP boiler at Clement Pappas, a juice bottler located in Ontario, California. The Super Boiler combustion system is based on two stage combustion which combines air staging, internal flue gas recirculation, inter-stage cooling, and unique fuel-air mixing technology to achieve low emissions rather than external flue gas recirculation which is most commonly used today. The two-stage combustion provides lower emissions because of the integrated design of the boiler and combustion system which permit precise control of peak flame temperatures in both primary and secondary stages of combustion. To reduce equipment size, the Super Boiler's dual furnace design increases radiant heat transfer to the furnace walls, allowing shorter overall furnace length, and also employs convective tubes with extended surfaces that increase heat transfer by up to 18-fold compared to conventional bare tubes. In this way, a two-pass boiler can achieve the same efficiency as a traditional three or four-pass firetube boiler design. The Super Boiler is consequently

  6. 超声波检测技术在锅炉受热面管氧化皮检测中的应用%Application of Ultrasonic Technique in Measuring Oxide-layer Thickness in Boiler Heat-absorbing Tube Inspection

    Institute of Scientific and Technical Information of China (English)

    张凤安; 朱邦同

    2014-01-01

    Measuring the thickness of oxide-layer in heat-absorbing tubes is always an important means to prevent heat-absorbing tubes from leaking.This paper mainly introduced the application of ultrasonic technique in measuring oxide-layer thickness in boiler finishing superheater of some power plant.By comparing the test results by microscope and endoscopy with the field data,it further validates the accuracy and reliability of this technology.At the same time,comparing this tech-nology with traditional RT technology and the measurement of oxide-layer in stainless steel tube bend was done and the measurement of oxide-layer by cutting tube was also done,and its advantages and prospect were pointed out.It has the cer-tain instruction function to guide the boiler inspection and guarantee the safe and economic operation of boilers.%锅炉受热面管氧化皮检测历来都是预防锅炉爆管的重要手段,主要介绍了超声波检测技术在某电厂锅炉末级过热器管内壁氧化皮检测中的实际应用,通过将超声波检测结果与内窥镜检查以及显微镜下的测量结果进行比较,进一步验证了该技术的准确性和可靠性。同时,将该技术与传统的射线拍片技术、不锈钢氧化皮堆积测量技术和割管取样测量等方法做了比较,指出超声波检测技术的优势及应用前景,对指导锅炉检修及保障锅炉安全经济运行具有一定的指导作用。

  7. Tube Wall Temperature Calculation and Oxide Film Effects Analysis on High-temperature Confection Heating Surface of Utility Boiler%电站锅炉高温对流受热面壁温计算及氧化膜影响分析

    Institute of Scientific and Technical Information of China (English)

    吴恺; 王甲安; 吕伟为; 徐鸿

    2015-01-01

    火电厂锅炉爆管事故是电厂事故中最常见的情形之一,爆管事故的发生对电厂的安全性经济性影响巨大。而此类问题的发生和锅炉管壁温度超温密不可分,因此若能全面准确可靠的监测受热面管壁温度将对电厂意义重大。但是电厂锅炉由于炉内壁温测点安装较困难,另外由于炉内温度高,即使安装了测点,测点通常寿命不长。通常安装在炉外大包内的壁温测点只能在一定程度上反应管道内部介质的温度,而对于最危险处的壁温却无法直接得到。本文针对此问题,对壁温计算模型进行了分析,利用Fluent数值模拟软件进行了燃烧模拟计算,使用Delphi语言对该计算模型编制了相应的程序,结合某电厂2028t/h锅炉实例进行计算,并假设氧化膜存在对结果的影响进行了再次计算和分析。能对电厂锅炉的安全运行提供正确的指导,也可为电厂锅炉管道的及时检修提出指导,具有重要的工程实用价值。%Power plant boiler pipe rupture accident is one of the most common situations in power plant. Tube-burst accident has had a huge impact on the safety and economy in Power plant. The occurrence of such problems are inextricably linked with the boiler tube wall over-temperature, so it is great significance to comprehensively accurately and reliably mon-itor the tube wall temperature of heat exchangers in power plants. But due to the power plant boiler furnace wall temperature measuring point is difficult to install. Even if installed, the high temperature in the furnace usually makes it not long life. For the most dangerous place, the wall temperature cannot directly obtain.Aimed at this problem, this author analyze the wall temperature calculation model, combined with power plant example of 2028 t/h boiler, use Delphi language to compile the corresponding program for the calculation model, use numerical simulation software Fluent to

  8. Solved and unsolved problems in boiler systems. Learning from accidents

    International Nuclear Information System (INIS)

    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/m3, 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/m2. 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)

  9. WASTE HEAT RECOVERY FROM BOILER OF LARGE-SCALE TEXTILE INDUSTRY

    OpenAIRE

    Prateep Pattanapunt; Kanokorn Hussaro; Tika Bunnakand; Sombat Teekasap

    2013-01-01

    Many industrial heating processes generate waste energy in textile industry; especially exhaust gas from the boiler at the same time reducing global warming. Therefore, this article will present a study the way to recovery heat waste from boiler exhaust gas by mean of shell and tube heat exchanger. Exhaust gas from boiler dyeing process, which carries a large amount of heat, energy consumptions could be decrease by using of waste-heat recovery systems. In this study, using ANASYS simulation p...

  10. Modelling transition states of a small once-through boiler

    Energy Technology Data Exchange (ETDEWEB)

    Talonpoika, T. [Lappeenranta Univ. of Technology (Finland). Dept. of Energy Technology

    1997-12-31

    This article presents a model for the unsteady dynamic behaviour of a once-through counter flow boiler that uses an organic working fluid. The boiler is a compact waste-heat boiler without a furnace and it has a preheater, a vaporiser and a superheater. The relative lengths of the boiler parts vary with the operating conditions since they are all parts of a single tube. The boiler model is presented using a selected example case that uses toluene as the process fluid and flue gas from natural gas combustion as the heat source. The dynamic behaviour of the boiler means transition from the steady initial state towards another steady state that corresponds to the changed process conditions. The solution method chosen is to find such a pressure of the process fluid that the mass of the process fluid in the boiler equals the mass calculated using the mass flows into and out of the boiler during a time step, using the finite difference method. A special method of fast calculation of the thermal properties is used, because most of the calculation time is spent in calculating the fluid properties. The boiler is divided into elements. The values of the thermodynamic properties and mass flows are calculated in the nodes that connect the elements. Dynamic behaviour is limited to the process fluid and tube wall, and the heat source is regarded as to be steady. The elements that connect the preheater to the vaporiser and the vaporiser to the superheater are treated in a special way that takes into account a flexible change from one part to the other. The initial state of the boiler is received from a steady process model that is not a part of the boiler model. The known boundary values that may vary during the dynamic calculation were the inlet temperature and mass flow rates of both the heat source fluid and the process fluid. The dynamic boiler model is analysed for linear and step charges of the entering fluid temperatures and flow rates. The heat source side tests show that

  11. Clean Firetube Boiler Waterside Heat Transfer Surfaces, Energy Tips: STEAM, Steam Tip Sheet #7 (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2012-04-01

    A steam energy tip sheet for the Advanced Manufacturing Office (AMO). The prevention of scale formation in firetube boilers can result in substantial energy savings. Scale deposits occur when calcium, magnesium, and silica, commonly found in most water supplies, react to form a continuous layer of material on the waterside of the boiler heat exchange tubes. Scale creates a problem because it typically possesses a thermal conductivity, an order of magnitude less than the corresponding value for bare steel. Even thin layers of scale serve as an effective insulator and retard heat transfer. The result is overheating of boiler tube metal, tube failures, and loss of energy efficiency. Fuel consumption may increase by up to 5% in firetube boilers because of scale. The boilers steam production may be reduced if the firing rate cannot be increased to compensate for the decrease in combustion efficiency. Energy losses as a function of scale thickness and composition are given. Any scale in a boiler is undesirable. The best way to deal with scale is not to let it form in the first place. Prevent scale formation by: (1) Pretreating of boiler makeup water (using water softeners, demineralizers, and reverse osmosis to remove scale-forming minerals); (2) Injecting chemicals into the boiler feedwater; and (3) Adopting proper boiler blowdown practices.

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

    International Nuclear Information System (INIS)

    Advanced Gas-Cooled Reactors (AGRs) operated in the UK by EDF Energy have once-through boilers, which deliver superheated steam at high temperature (∼500 deg. C) and pressure (∼150 bar) to the HP turbine. The boilers have either a serpentine or helical geometry for the tubing of the main heat transfer sections of the boiler and each individual tube is fabricated from mild steel, 9%Cr1%Mo and Type 316 austenitic stainless steel tubing. Type 316 austenitic stainless steel is used for the secondary (final) superheater and steam tailpipe sections of the boiler, which, during normal operation, should operate under dry, superheated steam conditions. This is achieved by maintaining a specified margin of superheat at the upper transition joint (UTJ) between the 9%Cr1%Mo primary superheater and the Type 316 secondary superheater sections of the boiler. Operating in this mode should eliminate the possibility of stress corrosion cracking of the Type 316 tube material on-load. In recent years, however, AGRs have suffered a variety of operational problems with their boilers that have made it difficult to maintain the specified superheat margin at the UTJ. In the case of helical boilers, the combined effects of carbon deposition on the gas side and oxide deposition on the waterside of the tubing have resulted in an increasing number of austenitic tubes operating with less than the specified superheat margin at the UTJ and hence the possibility of wetting the austenitic section of the boiler. Some units with serpentine boilers have suffered creep-fatigue damage of the high temperature sections of the boiler, which currently necessitates capping the steam outlet temperature to prevent further damage. The reduction in steam outlet temperature has meant that there is an increased risk of operation with less than the specified superheat margin at the UTJ and hence stress corrosion cracking of the austenitic sections of the boiler. In order to establish the risk of stress

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

    Energy Technology Data Exchange (ETDEWEB)

    Tice, D.R.; Platts, N.; Raffel, A.S. [Serco Assurance (United Kingdom); Rudge, A. [British Energy Generation Ltd. (United Kingdom)

    2002-07-01

    An extensive programme of work has been carried out to evaluate two candidate inhibited cleaning solutions for possible implementation on plant, which would be the first chemical clean of an AGR boiler. The two candidate cleaning solutions considered were a Stannine-inhibited citric acid/formic acid mixture (GOM106) and inhibited hydrofluoric acid. Citric acid-based cleaning processes are widely used within the UK Power Industry. The GOM106 solution, comprising a mixture of 3% citric acid, 0.5% formic acid and 0.05% Stannine LTP inhibitor, buffered with ammonia to pH 3.5, was developed specifically for the AGR boilers during the 1970's. Although a considerable amount of materials testing work was carried out by British Energy's predecessor companies to produce a recommended cleaning procedure there were some remaining concerns with the use of GOM106, from these earlier studies, for example, an increased risk of pitting attack associated with the removal of thick 9Cr oxide deposits and a risk of unacceptable damage in critical locations such as the upper transition joints and other weld locations. Hence, additional testing was still required to validate the solution for use on plant. Inhibited hydrofluoric acid (HFA) was also evaluated as an alternative reagent to GOM106. HFA has been used extensively for cleaning mild and low'alloy steel boiler tubes in fossil-fired plant in the UK and elsewhere in Europe and is known to remove oxide quickly. Waste treatment is also easier than for the GOM106 process and some protection against damage to the boiler tube materials is provided by complexing of fluoride with ferric ion. Validation of the potential reagents and inhibitors was achieved by assessing the rate and effectiveness of oxide removal from specimens of helical boiler tubing and welds, together with establishing the extent of any metal loss or localised damage. The initial materials testing resulted in the inhibited ammoniated citric / formic acid

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

    International Nuclear Information System (INIS)

    An extensive programme of work has been carried out to evaluate two candidate inhibited cleaning solutions for possible implementation on plant, which would be the first chemical clean of an AGR boiler. The two candidate cleaning solutions considered were a Stannine-inhibited citric acid/formic acid mixture (GOM106) and inhibited hydrofluoric acid. Citric acid-based cleaning processes are widely used within the UK Power Industry. The GOM106 solution, comprising a mixture of 3% citric acid, 0.5% formic acid and 0.05% Stannine LTP inhibitor, buffered with ammonia to pH 3.5, was developed specifically for the AGR boilers during the 1970's. Although a considerable amount of materials testing work was carried out by British Energy's predecessor companies to produce a recommended cleaning procedure there were some remaining concerns with the use of GOM106, from these earlier studies, for example, an increased risk of pitting attack associated with the removal of thick 9Cr oxide deposits and a risk of unacceptable damage in critical locations such as the upper transition joints and other weld locations. Hence, additional testing was still required to validate the solution for use on plant. Inhibited hydrofluoric acid (HFA) was also evaluated as an alternative reagent to GOM106. HFA has been used extensively for cleaning mild and low'alloy steel boiler tubes in fossil-fired plant in the UK and elsewhere in Europe and is known to remove oxide quickly. Waste treatment is also easier than for the GOM106 process and some protection against damage to the boiler tube materials is provided by complexing of fluoride with ferric ion. Validation of the potential reagents and inhibitors was achieved by assessing the rate and effectiveness of oxide removal from specimens of helical boiler tubing and welds, together with establishing the extent of any metal loss or localised damage. The initial materials testing resulted in the inhibited ammoniated citric / formic acid reagent being

  15. 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

  16. 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

  17. Materials for the pulp and paper industry. Section 1: Development of materials for black liquor recovery boilers

    Energy Technology Data Exchange (ETDEWEB)

    Keiser, J.R.; Hubbard, C.R.; Payzant, E.A. [Oak Ridge National Lab., TN (United States)] [and others

    1997-04-01

    Black liquor recovery boilers are essential components of kraft pulp and paper mills because they are a critical element of the system used to recover the pulping chemicals required in the kraft pulping process. In addition, the steam produced in these boilers is used to generate a significant portion of the electrical power used in the mill. Recovery boilers require the largest capital investment of any individual component of a paper mill, and these boilers are a major source of material problems in a mill. The walls and floors of these boilers are constructed of tube panels that circulate high pressure water. Molten salts (smelt) accumulate on the floor of recovery boilers, and leakage of water into the boiler can result in a violent explosion when the leaked water instantly vaporizes upon contacting the molten smelt. Because corrosion of the conventionally-used carbon steel tubing was found to be excessive in the lower section of recovery boilers, use of stainless steel/carbon steel co-extruded tubing was adopted for boiler walls to lessen corrosion and reduce the likelihood of smelt/water explosions. Eventually, this co-extruded or composite (as it is known in the industry) tubing was selected for use as a portion or all of the floor of recovery boilers, particularly those operating at pressures > 6.2 MPa (900 psi), because of the corrosion problems encountered in carbon steel floor tubes. Since neither the cause of the cracking nor an effective solution has been identified, this program was established to develop a thorough understanding of the degradation that occurs in the composite tubing used for walls and floors. This is being accomplished through a program that includes collection and review of technical reports, examination of unexposed and cracked tubes from boiler floors, computer modeling to predict residual stresses under operating conditions, and operation of laboratory tests to study corrosion, stress corrosion cracking, and thermal fatigue.

  18. 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,...

  19. Charting the boiler market

    International Nuclear Information System (INIS)

    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.

  20. Studies Concerning Water-Surface Deposits in Recovery Boilers

    International Nuclear Information System (INIS)

    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

  1. Cause Analysis and Preventive Measures on Bursting of High Temperature Superheater Tubes of 680 t/h Power Station Boiler%680t/h电站锅炉高温过热器爆管原因分析及预防措施

    Institute of Scientific and Technical Information of China (English)

    王小聪; 黎华; 马括; 卢忠铭

    2012-01-01

    Bursting of high temperature superheater tubes of 680 t/h power station boiler coccured twice reeently, and macroscopic examination, chemical compositions analysis and metallographic examination were investigated to find the casuse, the results showed that the failure was due to overheat which led to primary creep, then some effective prevention measures were taken.%某台680t/h电站锅炉高温过热器最近发生两起爆管事故,通过对爆管样管进行宏观检验、化学成分分析和金相检验判断爆管的根本原因。结果表明:由于长时间超温运行导致管子早期蠕变引起爆管,并采取了有效的预防措施。

  2. Application of the decree 2910 for coal fired boilers; Application de l`arrete 2910 aux chaudieres a charbon

    Energy Technology Data Exchange (ETDEWEB)

    Hing, K. [CDF Energie, Charbonnages de France, 92 - Rueil-Malmaison (France)

    1997-12-31

    The impacts of the new French decree 2910 concerning the classification of all combustion equipment with regards to their energy sources, energy efficiency and pollution control, on 2 to 20 MW coal-fired boilers, are discussed, with emphasis on their pollutant emissions (SO{sub 2}, NO{sub x} and ashes). The compositions of several coals is presented and the various types of coal-fired boilers adapted to the new decree are presented: automatic boilers, dense fluidized bed boilers, vibrating and chain grids with fume tubes and water tubes

  3. Steam boiler technology

    Energy Technology Data Exchange (ETDEWEB)

    Teir, S.

    2003-07-01

    This book is the published version of the e-book with the same name. The interactive lecture slides, which accompany most chapters, exist only in the online version and on the attached CD-Rom. The Steam Boiler Technology e-book is the main course book for the course on steam boiler technology provided by the Laboratory of Energy Engineering and Environmental Protection at Helsinki University of Technology. The steam boiler technology e-Book is provided by the Laboratory of Energy Engineering and Environmental Protection at Helsinki University of Technology. The book covers the basics and the history of steam generation, modern boilers types and applications, steam/water circulation design, feedwater and steam systems components, heat exchangers in steam boilers, boiler calculations, thermal design of heat exchangers. The chapters of the second edition have been corrected based on reader and reviewer comments, and four new chapters have been added. The user interface of the electronic version has also been updated. The password for the online book will be changed once a year. If you have problems accessing the online book, or need a new password, please contact sebastian.teir@hut.fi.

  4. A Flue Gas Tube for Thermoelectric Generator

    DEFF Research Database (Denmark)

    2013-01-01

    The invention relates to a flue gas tube (FGT) (1) for generation of thermoelectric power having thermoelectric elements (8) that are integrated in the tube. The FTG may be used in combined heat and power (CHP) system (13) to produce directly electricity from waste heat from, e.g. a biomass boiler...

  5. MODELLING, SIMULATING AND OPTIMIZING BOILERS

    DEFF Research Database (Denmark)

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

    In the present work a framework for optimizing the design of boilers for dynamic operation has been developed. A cost function to be minimized during the optimization has been formulated and for the present design variables related to the Boiler Volume and the Boiler load Gradient (i.e. ring rate...... on the boiler) have been dened. Furthermore a number of constraints related to: minimum and maximum boiler load gradient, minimum boiler size, Shrinking and Swelling and Steam Space Load have been dened. For dening the constraints related to the required boiler volume a dynamic model for simulating...... the boiler performance has been developed. Outputs from the simulations are shrinking and swelling of water level in the drum during for example a start-up of the boiler, these gures combined with the requirements with respect to allowable water level uctuations in the drum denes the requirements with...

  6. Ash particle erosion on steam boiler convective section

    Energy Technology Data Exchange (ETDEWEB)

    Meuronen, V.

    1997-12-31

    In this study, equations for the calculation of erosion wear caused by ash particles on convective heat exchanger tubes of steam boilers are presented. A new, three-dimensional test arrangement was used in the testing of the erosion wear of convective heat exchanger tubes of steam boilers. When using the sleeve-method, three different tube materials and three tube constructions could be tested. New results were obtained from the analyses. The main mechanisms of erosion wear phenomena and erosion wear as a function of collision conditions and material properties have been studied. Properties of fossil fuels have also been presented. When burning solid fuels, such as pulverized coal and peat in steam boilers, most of the ash is entrained by the flue gas in the furnace. In bubbling and circulating fluidized bed boilers, particle concentration in the flue gas is high because of bed material entrained in the flue gas. Hard particles, such as sharp edged quartz crystals, cause erosion wear when colliding on convective heat exchanger tubes and on the rear wall of the steam boiler. The most important ways to reduce erosion wear in steam boilers is to keep the velocity of the flue gas moderate and prevent channelling of the ash flow in a certain part of the cross section of the flue gas channel, especially near the back wall. One can do this by constructing the boiler with the following components. Screen plates can be used to make the velocity and ash flow distributions more even at the cross-section of the channel. Shield plates and plate type constructions in superheaters can also be used. Erosion testing was conducted with three types of tube constructions: a one tube row, an in- line tube bank with six tube rows, and a staggered tube bark with six tube rows. Three flow velocities and two particle concentrations were used in the tests, which were carried out at room temperature. Three particle materials were used: quartz, coal ash and peat ash particles. Mass loss

  7. Integrated boiler, superheater, and decomposer for sulfuric acid decomposition

    Science.gov (United States)

    Moore, Robert; Pickard, Paul S.; Parma, Jr., Edward J.; Vernon, Milton E.; Gelbard, Fred; Lenard, Roger X.

    2010-01-12

    A method and apparatus, constructed of ceramics and other corrosion resistant materials, for decomposing sulfuric acid into sulfur dioxide, oxygen and water using an integrated boiler, superheater, and decomposer unit comprising a bayonet-type, dual-tube, counter-flow heat exchanger with a catalytic insert and a central baffle to increase recuperation efficiency.

  8. 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...

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

    International Nuclear Information System (INIS)

    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.

  10. PERFORMANCE EVALUATION OF BOILERS (80 AND 40 TPH AND 21MW STEAM TURBINE OF COGEN PLANT

    Directory of Open Access Journals (Sweden)

    D.P.TAWARE

    2014-06-01

    Full Text Available The proposed study is conducted at The Malegaon Sugar Mills, Baramati, and District Pune. Data is collected for a high pressure 80 TPH & 40TPH bagasse fired boiler. The boilers are natural circulation and bi-drum water tube type. The both boilers are equipped with super heater, air heater and economizer in order to utilize maximum available heat of flue gases. Boiler efficiency is calculated by indirect method. Also plant has 21 MW cogeneration capacity, with two turbines are installed with capacity 14MW (Back Pressure Type & 7MW (Extraction Cum Condensing Type. From the heat input given to turbines per unit of electricity generated, the turbine heat rate is calculated. Different instruments and devices are used to record the different parameters of both boilers & turbines. Steam produced per ton of bagasse is being found out for both boilers.

  11. In search of an alternative high-pressure boiler water treatment program

    Energy Technology Data Exchange (ETDEWEB)

    Janssen, Peter [Sitech Manufacturing Services, Geleen (Netherlands); Savelkoul, Jo

    2012-07-15

    In the early eighties, traditional inorganic chemistry treated high-pressure (HP) industry boilers, in the Netherlands and elsewhere, suffered from boiler tube failures (BTFs). Benchmarking and root cause analyses showed BTFs to be indisputably connected to a combination of high heat transfer rates and magnetite deposits. From 1980 to 1995, research was carried out on boiler water problems and on treatment of chemicals both in HP autoclaves at the DSM Water Laboratory and in real DSM plant boiler systems. Moreover, thorough desk studies were carried out. Polyamine treatment came out as the most promising option to mitigate BTFs. It has been in use in Dutch industrial high-pressure boilers since 1996. This paper presents results from our research and from boiler and turbine experience and inspections totaling 15 years of polyamine treatment. (orig.)

  12. Development of Self-Powered Wireless-Ready High Temperature Electrochemical Sensors for In-Situ Corrosion Monitoring for Boiler Tubes in Next Generation Coal-based Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xingbo [West Virginia Univ., Morgantown, WV (United States)

    2015-06-30

    The key innovation of this project is the synergy of the high temperature sensor technology based on the science of electrochemical measurement and state-of-the-art wireless communication technology. A novel self-powered wireless high temperature electrochemical sensor system has been developed for coal-fired boilers used for power generation. An initial prototype of the in-situ sensor demonstrated the capability of the wireless communication system in the laboratory and in a pilot plant (Industrial USC Boiler Setting) environment to acquire electrochemical potential and current signals during the corrosion process. Uniform and localized under-coal ash deposit corrosion behavior of Inconel 740 superalloy has been studied at different simulated coal ash hot corrosion environments using the developed sensor. Two typical potential noise patterns were found to correlate with the oxidation and sulfidation stages in the hot coal ash corrosion process. Two characteristic current noise patterns indicate the extent of the corrosion. There was a good correlation between the responses of electrochemical test data and the results from corroded surface analysis. Wireless electrochemical potential and current noise signals from a simulated coal ash hot corrosion process were concurrently transmitted and recorded. The results from the performance evaluation of the sensor confirm a high accuracy in the thermodynamic and kinetic response represented by the electrochemical noise and impedance test data.

  13. The impact of biomass co-combustion on the erosion of boiler convection surfaces

    International Nuclear Information System (INIS)

    Highlights: • The lower ash content of biomass, the more quickly ash settles on boiler tubes. • The higher share of biomass, the more quickly ash settles on boiler tubes. • Operation of jet blowers involves intense fly ash erosive wear of heating surfaces • Application of acoustic or microblasting technology is advantageous. - Abstract: The erosive wear of boiler tubes caused by fly ash in coal combustion flue gases has been studied for a long time. However, there are practically no data concerning the intensity of the erosion of the heating surfaces of boilers fired with both coal and biomass, and thus it is difficult to design these particular areas appropriately. The essential problem is the tendency of the fly ash from biomass combustion to produce ash deposits on the boiler convection surfaces and to cause slagging on the radiant surfaces. In such cases, both an increase in the deposits and a shortening of the time over which the ash fouling accumulates to the maximum level are observed. Consequently, if the boiler is fitted with steam or air blowers, they are started more frequently; if not, they have to be installed. The research conducted here proves that the situation leads to serious damage to the tubes, which results from the erosion caused by ash particles carried by the blowing agent jet. The authors of this paper attempt to make a quantitative evaluation of the impact of co-firing two types of biomass (coniferous wood chips and willow wood chips) on both types of tube erosion

  14. Investigation and Treatment of Defects in T23 Steel Welding Joint for water-wall tubes in Ultra-supercritical Tower-type Boiler%超超临界机组塔式炉T23水冷壁缺陷成因分析及治理研究

    Institute of Scientific and Technical Information of China (English)

    宫广正

    2014-01-01

    T23管焊接接头失效已成为超超临界机组安全运行的重大隐患。以某电厂百万超超临界塔式锅炉为例,对锅炉水冷壁T23管开裂原因进行分析,发现焊接接头韧性不足和残余应力水平较高是导致失效的主要因素,据此提出了T23钢管焊接接头缺陷的治理措施。%The failure of T23 Steel tube welded joints has become an important hidden danger to safety operation of ultra-su-percritical units. This paper investigated the cracking reasons of T23 Steel water-wall tube in a 1,000 MW ultra-supercritical tower-type boiler and found the major causes are lacking of the toughness and high level of the residual stress in welding joints. According to the result, a treatment measure of the T23 Steel welded joints was suggested.

  15. 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.

  16. 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...

  17. Control Properties of Bottom Fired Marine Boilers

    OpenAIRE

    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 t...

  18. 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

  19. Geometrical Optimization for Outlet Tubes at Header of Top Roof Superheater in a Utility Boiler of a Power Plant%某电厂汽包锅炉过热器顶棚管联箱结构优化研究

    Institute of Scientific and Technical Information of China (English)

    吕玉贤; 庞力平; 李文学

    2014-01-01

    针对某电厂锅炉顶棚过热器频繁爆管现象,建立了与现场实际相同的几何模型,采用计算流体动力学方法对联箱内部流动情况进行数值研究。研究发现联箱三通附近由于静压分布异常,导致引入管周边的分支管静压较低,流量分配相对减少,发生传热恶化,进而发生爆管。该文提出优化的几何结构,通过对特定分支管引出方向进行调整,显著提升了并联分支管流量分配的均匀性,为电站锅炉分配联箱设计和结构优化提供一定的参考。%Numerical simulation was performed on the internal flow of header using the method of computational fluid dynamics with geometry model builded the same as practical field for the frequent rupture of roof superheater in a power station. The results indicate that due to the abnormal static pressure distribution in the area of Tee-junction of header, the static pressure of the branch pipes around inlet tube is so low, and the mass flow rate decreases relatively, then the heat transferation of tubes deteriorates,finally the tubes rupture. This paper proposes an improved geometric construction. By changing the leading direction of specific branch pipes, the uniformity of mass flow distribution in branch pipes promotes significient. It will offer a great reference for further design and optimization of distribution header in power station boilers.

  20. Applied studies in advanced boiler technology for Rankine cycle power systems

    Energy Technology Data Exchange (ETDEWEB)

    Paul, F.W.; Negreanu, M.J.

    1978-02-01

    A study is presented on a new rotational boiler design which has improved passive dynamic response and two-phase flow stability characteristics. A survey of small boiler manufacturers in the United States indicated that currently available designs are based on steady-state operating requirements rather than for dynamic performance. Recent work by EPA and ERDA which addressed boiler designs for mobile automotive Rankine cycle power systems showed that boilers of a monotube or multipass tube configuration design could be developed which were physically compact, but still were subject to the two-phase flow instability problem when coupled within an operating power system. The objectives of this work were to evaluate alternative boiler configurations which would improve boiler dynamic response and also have good two-phase liquid-vapor interface flow stability. The major physical design limitation of any boiler is the small external hot gas heat transfer coefficient. Such a low coefficient requires considerable design enhancements to increase the rate of energy transfer to the circulation system fluid. The rotational boiler is a physical design configuration which addresses this problem. The results of an analytic study using several mathematical model formulations showed that a rotational boiler could have a passive response time constant which was approximately one-half the magnitude for an equivalent single pass monotube boiler. An experimental prototype rotational boiler was designed, manufactured and tested, with the experimental results confirming that the experimental passive response time constants were comparable to the estimates from the analytic models. The experimental boiler operating in two-phase flow was found to be stable and responsive to external inputs. A rotational boiler configuration is a good alternative design configuration for small compact vapor generator designs based on fast transient passive response and two-phase flow stability.

  1. The economics of repeated tube thickness surveys

    International Nuclear Information System (INIS)

    The use of tube thickness surveys in boilers is an example of a commonly applied condition monitoring (CM) technique for maintenance and it leads to condition-based maintenance (CBM) of the boiler tubes. There are, however, limits to the economics of this type of strategy which are frequently overlooked in discussion of CBM strategies. This paper considers several models of maintenance strategies. Conditions in which breakdown maintenance (BM), routine total replacement (routine maintenance, RM) and condition-based replacement (which for simplicity is referred to as CM) are considered. Some general rules about the economical range of each strategy are developed. The case study examines the use of ultrasonic testing of boiler tubes in power stations in some detail

  2. Installations of SNCR on bark-fired boilers

    International Nuclear Information System (INIS)

    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 NOx reduction vary between the installations depending on boiler, fuel and operation. The emissions are between 45 and 100 mg NO2/MJ fuel input and the NOx reduction rates are in most installations between 30 and 40 %, the lowest 20 and the highest 70 %. 13 figs, 3 tabs

  3. Gas mixing processes in nuclear AGR boilers

    International Nuclear Information System (INIS)

    To ensure the safe operation and control of Nuclear (A.G.R.) boilers, 2-D computational models are currently under development. The aim of these models is to predict the flow and temperature distribution of the gas and water side under different operational conditions. These models are based on numerical solutions of the 2-D flow and heat transfer equations for turbulent flow in boilers. Measurements on a closely pitched tube bank with water cooling have demonstrated considerable discrepancies between experimental results and computer predictions. This investigation is therefore being carried out to study theoretically and experimentally the flow and heat transfer process under such a boiler condition. A two dimensional computer model has been developed which incorporates the effects of gas mixing and the interactions between the gas and water side. To cover the complete heat exchanger the governing equations are written in the lumped parameter form. The governing equations have been solved by a computer code written in FORTRAN-77. To test the validity of this model, the computer predictions have been compared with experimental results. Results to date indicate reasonable agreement with experiment and a further refinement of the computer model is indicated. (author)

  4. Optimization of Load Assignment to Boilers in Industrial Boiler Plants

    Institute of Scientific and Technical Information of China (English)

    CAO Jia-cong; QIU Guang; CAO Shuang-hua; LIU Feng-qiang

    2004-01-01

    Along with the increasing importance of sustainable energy, the optimization of load assignment to boilers in an industrial boiler plant becomes one of the major projects for the optimal operation of boiler plants. Optimal load assignment for power systems has been a long-lasting subject, while it is quite new for industrial boiler plants. The existing methods of optimal load assignment for boiler plants are explained and analyzed briefly in the paper. They all need the fuel cost curves of boilers. Thanks to some special features of the curves for industrial boilers, a new model referred to as minimized departure model (MDM) of optimization of load assignment for boiler plants is developed and proposed in the paper. It merely relies upon the accessible data of two typical working conditions to build the model, viz. the working conditions with the highest efficiency of a boiler and with no-load. Explanation of the algorithm of computer program is given, and effort is made so as to determine in advance how many and which boilers are going to work. Comparison between the results using MDM and the results reported in references is carried out, which proves that MDM is preferable and practicable.

  5. Superheater corrosion in kraft recovery boilers; Korrosion hos oeverhettare i sodapannor. En oeversikt och diskussion

    Energy Technology Data Exchange (ETDEWEB)

    Bruno, F. [AaF-IPK, Stockholm (Sweden)

    1997-02-01

    Corrosion seems to be the most essential factor limiting the life and the availability of kraft recovery boilers. The steam temperature from the kraft recovery boiler has, seen from the view of electricity production and steam turbine operation, traditionally been kept moderate, especially in comparison with steam data from normal utility power plants. So the corrosion of the superheaters has been more a limitation for the temperature of the steam produced by the boiler than a life length limitation. Both the pressure and the temperature of the steam are limited by corrosion. The temperature of the boiling water, and hence the pressure, is limited by the corrosion in the lower furnace. The temperature of the steam is limited by the corrosion in the superheater. Kraft boiler superheater corrosion is here governed not only by the boiler design, but more by the mill chemistry and boiler operation practice. This report discusses the formation and the properties of the deposits and their relation to boiler operation and the corrosion of the superheater tube material. We have tried to understand the corrosion in the kraft boiler superheaters better by comparing with the experience from the utility boilers. 86 refs, 79 figs

  6. Demonstration of coal reburning for cyclone boiler NO{sub x} control. Appendix, Book 1

    Energy Technology Data Exchange (ETDEWEB)

    1994-06-01

    Based on the industry need for a pilot-scale cyclone boiler simulator, Babcock Wilcox (B&W) designed, fabricated, and installed such a facility at its Alliance Research Center (ARC) in 1985. The project involved conversion of an existing pulverized coal-fired facility to be cyclone-firing capable. Additionally, convective section tube banks were installed in the upper furnace in order to simulate a typical boiler convection pass. The small boiler simulator (SBS) is designed to simulate most fireside aspects of full-size utility boilers such as combustion and flue gas emissions characteristics, fireside deposition, etc. Prior to the design of the pilot-scale cyclone boiler simulator, the various cyclone boiler types were reviewed in order to identify the inherent cyclone boiler design characteristics which are applicable to the majority of these boilers. The cyclone boiler characteristics that were reviewed include NO{sub x} emissions, furnace exit gas temperature (FEGT) carbon loss, and total furnace residence time. Previous pilot-scale cyclone-fired furnace experience identified the following concerns: (1) Operability of a small cyclone furnace (e.g., continuous slag tapping capability). (2) The optimum cyclone(s) configuration for the pilot-scale unit. (3) Compatibility of NO{sub x} levels, carbon burnout, cyclone ash carryover to the convection pass, cyclone temperature, furnace residence time, and FEGT.

  7. Resistance welding of tubes at low regidual pressure jn tube cavity

    International Nuclear Information System (INIS)

    The procedure of butt resistance welding of boilers in diameter of 32 mm at low residual pressure in tube cavities has been studied. It is shown that the creation of low residual pressure in tube cavity makes it possible to produce qualitative joints of tubes of the 20, 12Kh1MF, 12Kh18N12T steels. The maximum relative deformation in the butt zone should be in the range of 0.5...0.6

  8. Numerical simulation based cold tests for a tangentially fired boiler

    Institute of Scientific and Technical Information of China (English)

    XIANG Yuhua; ZHANG Jiayuan; ZHANG Xiaohui

    2012-01-01

    Such problems as flameout and serious slagging frequently occurred in a 170 t/h tangentially fired boiler burning inferior coals and with low load.Thus,cold tests were carried out to comprehensively investigate the performance of each air tube and the size and position of the tangential circle.Therefore,the cause and area of slagging in furnace can be determined.Thus,by numerical simulation on combustion,the optimal operation parameters for the boiler burning different coals under various loads conditions can be provided.The actual application showed that,the boiler fed with present coal can be long-term operated stably at 60% load,and its heat efficiency was up to 91%.Moreover,the abnormal flameout no longer occurred,and the slagging was alleviated a lot.

  9. New technique of the local heat flux measurement in combustion chambers of steam boilers

    Science.gov (United States)

    Taler, Jan; Taler, Dawid; Sobota, Tomasz; Dzierwa, Piotr

    2011-12-01

    A new method for measurement of local heat flux to water-walls of steam boilers was developed. A flux meter tube was made from an eccentric tube of short length to which two longitudinal fins were attached. These two fins prevent the boiler setting from heating by a thermal radiation from the combustion chamber. The fins are not welded to the adjacent water-wall tubes, so that the temperature distribution in the heat flux meter is not influenced by neighbouring water-wall tubes. The thickness of the heat flux tube wall is larger on the fireside to obtain a greater distance between the thermocouples located inside the wall which increases the accuracy of heat flux determination. Based on the temperature measurements at selected points inside the heat flux meter, the heat flux absorbed by the water-wall, heat transfer coefficient on the inner tube surface and temperature of the water-steam mixture was determined.

  10. Optimising boiler performance.

    Science.gov (United States)

    Mayoh, Paul

    2009-01-01

    Soaring fuel costs continue to put the squeeze on already tight health service budgets. Yet it is estimated that combining established good practice with improved technologies could save between 10% and 30% of fuel costs for boilers. Paul Mayoh, UK technical manager at Spirax Sarco, examines some of the practical measures that healthcare organisations can take to gain their share of these potential savings. PMID:19192603

  11. High-Temperature Graphitization Failure of Primary Superheater Tube

    Science.gov (United States)

    Ghosh, D.; Ray, S.; Roy, H.; Mandal, N.; Shukla, A. K.

    2015-12-01

    Failure of boiler tubes is the main cause of unit outages of the plant, which further affects the reliability, availability and safety of the unit. So failure analysis of boiler tubes is absolutely essential to predict the root cause of the failure and the steps are taken for future remedial action to prevent the failure in near future. This paper investigates the probable cause/causes of failure of the primary superheater tube in a thermal power plant boiler. Visual inspection, dimensional measurement, chemical analysis, metallographic examination and hardness measurement are conducted as the part of the investigative studies. Apart from these tests, mechanical testing and fractographic analysis are also conducted as supplements. Finally, it is concluded that the superheater tube is failed due to graphitization for prolonged exposure of the tube at higher temperature.

  12. Super Boiler 2nd Generation Technology for Watertube Boilers

    Energy Technology Data Exchange (ETDEWEB)

    Mr. David Cygan; Dr. Joseph Rabovitser

    2012-03-31

    This report describes Phase I of a proposed two phase project to develop and demonstrate an advanced industrial watertube boiler system with the capability of reaching 94% (HHV) fuel-to-steam efficiency and emissions below 2 ppmv NOx, 2 ppmv CO, and 1 ppmv VOC on natural gas fuel. The boiler design would have the capability to produce >1500 F, >1500 psig superheated steam, burn multiple fuels, and will be 50% smaller/lighter than currently available watertube boilers of similar capacity. This project is built upon the successful Super Boiler project at GTI. In that project that employed a unique two-staged intercooled combustion system and an innovative heat recovery system to reduce NOx to below 5 ppmv and demonstrated fuel-to-steam efficiency of 94% (HHV). This project was carried out under the leadership of GTI with project partners Cleaver-Brooks, Inc., Nebraska Boiler, a Division of Cleaver-Brooks, and Media and Process Technology Inc., and project advisors Georgia Institute of Technology, Alstom Power Inc., Pacific Northwest National Laboratory and Oak Ridge National Laboratory. Phase I of efforts focused on developing 2nd generation boiler concepts and performance modeling; incorporating multi-fuel (natural gas and oil) capabilities; assessing heat recovery, heat transfer and steam superheating approaches; and developing the overall conceptual engineering boiler design. Based on our analysis, the 2nd generation Industrial Watertube Boiler when developed and commercialized, could potentially save 265 trillion Btu and $1.6 billion in fuel costs across U.S. industry through increased efficiency. Its ultra-clean combustion could eliminate 57,000 tons of NOx, 460,000 tons of CO, and 8.8 million tons of CO2 annually from the atmosphere. Reduction in boiler size will bring cost-effective package boilers into a size range previously dominated by more expensive field-erected boilers, benefiting manufacturers and end users through lower capital costs.

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

    OpenAIRE

    Li Sun; Junyi Dong; Donghai Li; Yuqiong Zhang

    2014-01-01

    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 d...

  14. The effect of water quality on reliability of boiler plants performance

    OpenAIRE

    Gajić Anto S.; Tomić Milorad V.; Pavlović Ljubica J.; Pavlović Miomir G.

    2010-01-01

    This paper presents sources and types of corrosion processes of boiler tube system of the Thermal Power Plant "Ugljevik". The main goal in the electric power production is to achieve lower prices, which can only be done by providing low maintenance costs. While it is not possible to completely stop corrosion, it could be slowed down and it's effects could be reduced. In order to reduce corrosion to a minimum on thermal power plants' vital equipment, particularly boilers, it is necessary to de...

  15. Analysis on Bust Problem of 12Cr1MoV High Temperature Superheater Tubes of Boiler%锅炉用12Cr1MoV 高温段过热管爆裂分析

    Institute of Scientific and Technical Information of China (English)

    刘长春; 沈玉力

    2014-01-01

    The burst reason of 12Cr1MoV steel tube of high temperature superheater tubes of a power plant was analyzed through macroscopic and metallographic examination .The results showed that local corrosion in high temperature led to mul-tiple cross crack sources , and propagation of the cracks caused vertical cracks to the same radial direction in two places . Local corrosion in high temperature and fully nodular pearlite were the root cause of the failure .%某电厂的12Cr1MoV(φ42×5mm)高温段过热器管发生爆裂。采用宏观和微观分析方法,分析了爆裂原因。结果表明,该爆裂模式为局部高温腐蚀引发多处横裂源进一步导致2处同一径向的纵裂。局部高温腐蚀及珠光体完全球化是这起事故的根本原因。

  16. Numerical simulation of a small-scale biomass boiler

    International Nuclear Information System (INIS)

    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.

  17. DOWNSCALE APPLICATION OF BOILER THERMAL CALCULATION APPROACH

    OpenAIRE

    Zelený, Zbynĕk; Hrdlička, Jan

    2016-01-01

    Commonly used thermal calculation methods are intended primarily for large scale boilers. Hot water small scale boilers, which are commonly used for home heating have many specifics, that distinguish them from large scale boilers especially steam boilers. This paper is focused on application of thermal calculation procedure that is designed for large scale boilers, on a small scale boiler for biomass combustion of load capacity 25 kW. Special issue solved here is influence of formation of dep...

  18. 我国700℃超超临界锅炉过热器管用高温合金选材探讨%Selection of Superalloys for Superheater Tubes of Domestic 700 ℃ A-USC Boilers

    Institute of Scientific and Technical Information of China (English)

    林富生; 谢锡善; 赵双群; 董建新

    2011-01-01

    简要介绍和比较了国内外700℃超超临界电站过热器和再热器管候选材料GH2984、Haynes 230、CCA 617、Nimonic 263、Inconel 740及其改型合金Inconel 740H的组织、持久强度和耐腐蚀性能等研究结果,对几种材料的强度、耐腐蚀性能、工艺性能和使用经济性进行了分析,并阐述了中国在发展700℃超超临界燃煤电站时锅炉用高温合金的选择.结果表明:Inconel 740H合金具有的持久强度最高、耐蚀性能最好,工艺性能和使用经济性良好,比Inconel 740合金具有更好的长期组织稳定性,它应是中国700℃超超临界锅炉过热器和再热器首选的管材;针对700℃超超临界机组用关键材料,提出了尽早开展自主研制,实现关键材料国产化的建议.%Research achievements on major candidate materials for superheater/reheater tubes of plants at home and abroad are reviewed and compared,such as the GH2984,Haynes 230,CCA 617,Nimonic 263,Inconel 740 and Inconel 740H,while their microstructure,stress rupture strength and corrosion resistance as well as their workability and economy were analyzed.A discussion is moreover carried out to the selection of superalloys for superheater/reheater tubes of domestic 700 ℃ A-USC power plants.Results show that superalloy Inconel 740H exhibits the highest stress rupture strength,strongest corrosion resistance,better workability and economy among above six alloys;its microstructure is more stable than that of Inconel 740 during long term aging,which is therefore at present believed to be most preferable for superheater/reheater tubes of domestic 700 ℃ A-USC power plants.For localization of key materials for relevant power plants,it is suggested that RD on these materials should be performed as early as possible.

  19. Small boiler uses waste coal

    Energy Technology Data Exchange (ETDEWEB)

    Virr, M.J. [Spinheat Ltd. (United States)

    2009-07-15

    Burning coal waste in small boilers at low emissions poses considerable problem. While larger boiler suppliers have successfully installed designs in the 40 to 80 MW range for some years, the author has been developing small automated fluid bed boiler plants for 25 years that can be applied in the range of 10,000 to 140,000 lbs/hr of steam. Development has centered on the use of an internally circulating fluid bed (CFB) boiler, which will burn waste fuels of most types. The boiler is based on the traditional D-shaped watertable boiler, with a new type of combustion chamber that enables a three-to-one turndown to be achieved. The boilers have all the advantages of low emissions of the large fluid boilers while offering a much lower height incorporated into the package boiler concept. Recent tests with a waste coal that had a high nitrogen content of 1.45% demonstrated a NOx emission below the federal limit of 0.6 lbs/mm Btu. Thus a NOx reduction on the order of 85% can be demonstrate by combustion modification alone. Further reductions can be made by using a selective non-catalytic reduction (SNCR) system and sulfur absorption of up to 90% retention is possible. The article describes the operation of a 30,000 lbs/hr boiler at the Fayette Thermal LLC plant. Spinheat has installed three ICFB boilers at a nursing home and a prison, which has been tested on poor-grade anthracite and bituminous coal. 2 figs.

  20. Steady and unsteady heat transfer in membrane water-wall of power plant boilers

    International Nuclear Information System (INIS)

    In this paper steady and unsteady conductive heat transfer in membrane walls of the boilers have been investigated. The furnace walls of the utility and large industrial boilers are constructed from membrane walls. The membrane walls consisting of parallel tubes connected longitudinally by fins have been considered. These types of the wall insulated outside and exposed to the furnace on the other, constitute an effective means of transferring heat from furnace to the water circulating inside the tubes. Analysis of heat transfer in membrane walls assemblies is an important step in design and sizing of the utility boiler's furnace. Because of geometric complexity and discontinuous properties of the fin-tube assembly, a numerical method is used, and for a simplified case of steady-state and no welding angle an analytical approach has been performed. The effect of the welding angle as well as fin width and thickness upon temperature distribution in the membrane walls have been considered. To obtain heat flux on the furnace sector of the tubes, the view factors between the flame considered as a paral led plane and the membrane walls has been evaluated. Also for the Start upof the boiler the distribution of temperature in membrane water-wall is obtained by finite element method and the effect of the tube thickness, fin thickness and width have been studied. It is also shown that the fin effectiveness as well as the insulated sector of the tube are closely related

  1. COMBINED BOILER WITH TPV

    OpenAIRE

    Björk, Magnus

    2013-01-01

    A TPV-system consists of a hot surface emitting heat radiation on a solar cell with a narrow bandgap.  A unit consisting of a boiler and a TPV-system has been constructed for testing of the performance of TPV cells. The emitter is heated by a fuel consisting of RME-oil. The radiation is collected and concentrated through two reflecting cones formed like a Faberge-egg, with an edge-type optical filter between the cones. The Faberge-egg is treated with electro-polishing in order to obtain a hig...

  2. Boilers a practical reference

    CERN Document Server

    Rayaprolu, Kumar

    2012-01-01

    AAbrasion and Abrasion Index (see Wear)Absolute or Dynamic Viscosity (æ) (see Viscosity in Fluid Characteristics)Acid Cleaning (see Commissioning)Acid Rain (also see Air Pollution Emissions and Controls and Gas Cleaning)Acid Sludge (see Refuse Fuels from Refinery in Liquid Fuels)Acid Smuts (see Oil Ash)Acoustic Soot Blowers (see Sonic Horns)Acoustic Enclosure (see Noise Control)Acoustic Leak Detection SystemAdiabatic Flame Temperature (see Combustion)Aeroderivative (see Types of GTs in Turbines, Gas)Ageing of Boiler ComponentsAgro-Fuels and FiringAir Ducts (see Draught Plant)Air Flow Measureme

  3. Boiler for ships; Hakuyo boira

    Energy Technology Data Exchange (ETDEWEB)

    Shimoda, F. [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan)

    1999-07-20

    In this paper, production and technology trend of boiler for ships in 1998 are described. The actual results of main boiler are as follows. As the main boiler for LNG ships, 4 boilers produced by Mitsui Engineering and Shipbuilding for Qatar Project, 8 produced by Kawasaki Heavy Industries for South Korea and 10 produced by Mitsubishi Heavy Industries for domestic use and South Korea. 1998 was an active year for the main boiler for ships. The auxiliary boiler of steam pressure of 16k to 25k equipping for tanker ships was 115 (4,441t/h of steam quantity in total), it greatly increased in comparison with 88 (3,172t/h) produced in the proceeding year. Donkey boilers of steam pressure of 6k to 10k equipping for container ships and bulk cargo was 147 (672t/h), and it substantially decreased in comparison with 274 (693t/h) of the proceeding year, but capacity per boiler increased. The gas exhaust economizer for turbo power generation plants was 6 produced for VLCC. (NEDO)

  4. 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.

  5. 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.

  6. Erosion–corrosion behaviour of Ni-based superalloy Superni-75 in the real service environment of the boiler

    Indian Academy of Sciences (India)

    T S Sidhu; S Prakash; R D Agrawal; Ramesh Bhagat

    2009-04-01

    The super-heater and re-heater tubes of the boilers used in thermal power plants are subjected to unacceptable levels of surface degradation by the combined effect of erosion–corrosion mechanism, resulting in the tube wall thinning and premature failure. The nickel-based superalloys can be used as boiler tube materials to increase the service life of the boilers, especially for the new generation tra-supercritical boilers. The aim of the present investigation is to evaluate the erosion–corrosion behaviour of Ni-based superalloy Superni-75 in the real service environment of the coal-fired boiler of a thermal power plant. The cyclic experimental study was performed for 1000 h in the platen superheater zone of the coal-fired boiler where the temperature was around 900°C. The corrosion products have been characterized with respect to surface morphology, phase composition and element concentration using the combined techniques of X-ray diffractometry (XRD), scanning electron microscopy/energy-dispersive analysis (SEM/EDAX) and electron probe micro analyser (EPMA). The Superni-75 performed well in the coal-fired boiler environment, which has been attributed mainly to the formation of a thick band of chromium in scale due to selective oxidation of the chromium.

  7. 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 analysis...... of the potential benefit from using a multivariable control strategy in favor of the current strategy based on single loop theory is carried out and proves that the interactions in the system are not negligible and a subsequent controller design should take this into account. A design using dynamical...... decoupling showed substantial improvement compared to a decentralized scheme based on sequential loop closing. Similar or better result is expected to be obtainable using a full Multiple input Multiple output scheme. Furthermore closed loop simulations, applying a linear controller to the nonlinear plant...

  8. Alternate tube plugging criteria for steam generator tubes

    Energy Technology Data Exchange (ETDEWEB)

    Cueto-Felgueroso, C.; Aparicio, C.B. [Tecnatom, S.A., Madrid (Spain)

    1997-02-01

    The tubing of the Steam Generators constitutes more than half of the reactor coolant pressure boundary. Specific requirements governing the maintenance of steam generator tubes integrity are set in Plant Technical Specifications and in Section XI of the ASME Boiler and Pressure Vessel Code. The operating experience of Steam Generator tubes of PWR plants has shown the existence of some types of degradatory processes. Every one of these has an specific cause and affects one or more zones of the tubes. In the case of Spanish Power Plants, and depending on the particular Plant considered, they should be mentioned the Primary Water Stress Corrosion Cracking (PWSCC) at the roll transition zone (RTZ), the Outside Diameter Stress Corrosion Cracking (ODSCC) at the Tube Support Plate (TSP) intersections and the fretting with the Anti-Vibration Bars (AVBs) or with the Support Plates in the preheater zone. The In-Service Inspections by Eddy Currents constitutes the standard method for assuring the SG tubes integrity and they permit the monitoring of the defects during the service life of the plant. When the degradation reaches a determined limit, called the plugging limit, the SG tube must be either repaired or retired from service by plugging. Customarily, the plugging limit is related to the depth of the defect. Such depth is typically 40% of the wall thickness of the tube and is applicable to any type of defect in the tube. In its origin, that limit was established for tubes thinned by wastage, which was the predominant degradation in the seventies. The application of this criterion for axial crack-like defects, as, for instance, those due to PWSCC in the roll transition zone, has lead to an excessive and unnecessary number of tubes being plugged. This has lead to the development of defect specific plugging criteria. Examples of the application of such criteria are discussed in the article.

  9. CFB boilers in multifuel application

    International Nuclear Information System (INIS)

    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)

  10. Needs-driven soot blowing in waste boilers; Behovsstyrd sotblaasning i avfallspannor

    Energy Technology Data Exchange (ETDEWEB)

    Niklasson, Fredrik; Davidsson, Kent

    2009-09-15

    The increased use of alternative and waste fuels has resulted in an increased number of plants having trouble with fouling and corrosion on boiler banks and superheater tubes. Frequent sootblowing will keep the surfaces relatively clean, but on the other hand, it may erode the tube material. An intelligent sootblowing system will initiate sootblowings on individual tube banks only when needed for that specific tube bank. Such a system depends on the detection of the degree of fouling of specific tube banks. In this project, the conditions for an intelligent sootblowing system at the waste fired boilers in Boraas are investigated from measured flows, temperatures and pressure drop. New thermocouples at the water tubes between the banks of the economiser have been installed and connected to the control and monitoring system of the boiler. From measured temperatures and flows, heat transfer coefficients are calculated and used to detect the fouling on the heat exchangers. A pressure transducer has been altered to measure the pressure over the boiler bank. At the superheaters, the measurements show a significant improvement of the heat transfer coefficients immediately following sootblowing. Thereafter, the heat transfer coefficients decline more slowly, almost linearly. The measurements indicate that the fouling rate is almost same for the two superheaters and do not motivate individual sootblowing sequences of the two superheaters. The pressure drop over the boiler bank was found too insensitive a measure to be used as an indicator for an intelligent sootblowing system, at least in this specific boiler. In the economiser, the decline of calculated heat transfer coefficients showed a relative rate of fouling on individual tube banks. The results show that the fouling rate is significantly higher in the top tube banks, which comes first in the direction of the flue gas, compared to downstream banks. Experiments by sootblowing the top tube bank more frequently than the

  11. Hybrid model of steam boiler

    International Nuclear Information System (INIS)

    In the case of big energy boilers energy efficiency is usually determined with the application of the indirect method. Flue gas losses and unburnt combustible losses have a significant influence on the boiler's efficiency. To estimate these losses the knowledge of the operating parameters influence on the flue gases temperature and the content of combustible particles in the solid combustion products is necessary. A hybrid model of a boiler developed with the application of both analytical modelling and artificial intelligence is described. The analytical part of the model includes the balance equations. The empirical models express the dependence of the flue gas temperature and the mass fraction of the unburnt combustibles in solid combustion products on the operating parameters of a boiler. The empirical models have been worked out by means of neural and regression modelling.

  12. 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.

  13. Combustion Characteristics of Oxy-fuel Burners for CO2 Capturing Boilers

    Science.gov (United States)

    Ahn, Joon; Kim, Hyouck Ju; Choi, Kyu Sung

    Oxy-fuel boilers have been developed to capture CO2 from the exhaust gas. A 50 kW class model burner has been developed and tested in a furnace type boiler. The burner has been scaled up to 0.5 and 3 MW class for fire-tube type boilers. The burners are commonly laid out in a coaxial type to effectively heat the combustion chamber of boilers. Burners are devised to support air and oxy-fuel combustion modes for the retrofitting scenario. FGR (flue gas recirculation) has been tried during the scale-up procedure. Oxy-fuel combustion yields stretched flame to uniformly heat the combustion chamber. It also provides the high CO2 concentration, which is over 90% in dry base. However, pure oxy-fuel combustion increases NO concentration, because of the reduced flow rate. The FGR can suppress the thermal NOx induced by the infiltration of the air.

  14. 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.

  15. The early operation of the helical once-through boilers at Heysham 1 and Hartlepool

    International Nuclear Information System (INIS)

    The Heysham 1 and Hartlepool AGR Reactors are equipped with 'pod' boilers set into the walls of the Pre-stressed Concrete Pressure Vessel. Each Reactor unit has eight pod boilers, which are of a somewhat unique single pressure, once through, helically wound type incorporating a reheater. The pods are provided with a limited amount of strain gauge and thermocouple instrumentation concentrated mainly in two specially instrumented boilers at each site. During Commissioning prior to power raising, extensive noise and vibration tests utilising the special attain gauge instrumented boilers, gave encouraging results. This has led to an increase in coolant gas mass flow of 5% above the design level. Following power raising in 1983 and 1984, detailed boiler performance testing, mainly using the special thermocouple instrumented boilers, showed that the actual behaviour differed from the computer design predictions. A major temperature tilt existed across the boiler tubes resulting in higher than predicted temperatures in the outer radius rows of tubes and the reverse situation in the inner tubes. The effect differed in magnitude between Hartlepool Reactor 1 and the other three Reactors probably due to construction differences. As a result output was initially limited to approximately 58% of design (380 MW (Generated)). A major programme of altering the flow control ferrules was carried out during the first statutory overhauls in 1985 and 1986. The initial results from Heysham 1 were not very encouraging (a gain of 70 MW(e)) but further computer model correlations led to revised patterns in Heysham and Hartlepool Reactor 2 which have since yielded improvements in output potential of up to 200 MW(e). The paper discusses the commissioning test results described above and describes the details of the extensive work carried out to achieve higher output. (author)

  16. Heat transfer characteristics of evaporator modules for a 2 t/h class multi burner boiler

    International Nuclear Information System (INIS)

    A finned tube type evaporator module has been applied to a water tube type industrial boiler adopting multiple burners. Fins change their geometry along the streamwise direction to maximize the performance, which makes it difficult to apply conventional bulk design procedure. A numerical simulation has been performed to evaluate the 2 or 3 dimensional effects such as inlet conditions. The numerical simulation also includes the conjugate heat transfer problem to predict the fin tip temperature.

  17. Heat transfer characteristics of air cross-flow for in-line arrangement of spirally corrugated tube and smooth tube bundles

    Institute of Scientific and Technical Information of China (English)

    LU Guo-dong; ZHOU Qiang-tai; TIAN Mao-cheng; CHENG Lin; YU Xiao-li

    2005-01-01

    An experimental study on heat transfer and resistance coefficients of linearly arranged smooth and spirally corrugated tube bundles in cross-flow was performed. The heat transfer and resistance coefficients are presented in this paper with transverse and longitudinal tube-pitch and tube geometries taken into account. The experiment's results can provide technical guidelines for application to horizontal air preheater with arranged in-line spirally corrugated tube bundles, especially to the air preheater for CFBCBs (Circulating Fluidized Bed Combustion Boilers).

  18. INDUSTRIAL BOILER RETROFIT FOR NOX CONTROL: COMBINED SELECTIVE NONCATALYTIC REDUCTION AND SELECTIVE CATALYTIC REDUCTION

    Science.gov (United States)

    The paper describes retrofitting and testing a 590 kW (2 MBtu/hr), oil-fired, three-pass, fire-tube package boiler with a combined selective noncatalytic reduction (SNCR) and selective catalytic reduction (SCR) system. The system demonstrated 85% nitrogen oxides (NOx) reduction w...

  19. Reason Analysis on Bursting Tube of High Temperature Boiler Tube of T92 Steel in Ultra Supercritical Unit%超超临界机组T92钢高温受热面管爆管原因分析

    Institute of Scientific and Technical Information of China (English)

    赵彦芬; 张路; 刘艳; 许万军

    2012-01-01

    The platen superheater tube failures of T92 steel has bursted in a ultra supercritical power plants. The bursting reason was analyzed by means of macroscopical inspection, chemical composition analysis, hardness testing, tensile strength testing, metallographie examination and so on. Results showed that the microstructure of the tube which didn't maintenance the typical lath martensite, the phase transformation at Ac~ ~Aca after short- term overheated. The strength decreased rapid distinctly, therefore the strength was not enough to endure the stress, finally the tube bursted. On the other hand, the relationship between the different microstructure and mechanical property was achieved by test in order to supervise for metal in thermal power plants for long term operation.%某电厂的后屏过热器T92钢管段发生爆管。通过宏观检验、化学成分分析、硬度检验、拉伸性能测试、金相检验以及相关计算分析了爆管的原因。结果表明:管段发生短时过热后,其显微组织为Acl-Ac3相变产物,失去了原典型的回火板条马氏体组织特征,材料强度大幅度降低,从而使得强度不足以抵抗管子的使用应力而发生爆管。另外,通过检验获得了不同状态下的组织与性能的对应关系,有利于长期运行中的金属监督检验。

  20. Boiler using combustible fluid

    Science.gov (United States)

    Baumgartner, H.; Meier, J.G.

    1974-07-03

    A fluid fuel boiler is described comprising a combustion chamber, a cover on the combustion chamber having an opening for introducing a combustion-supporting gaseous fluid through said openings, means to impart rotation to the gaseous fluid about an axis of the combustion chamber, a burner for introducing a fluid fuel into the chamber mixed with the gaseous fluid for combustion thereof, the cover having a generally frustro-conical configuration diverging from the opening toward the interior of the chamber at an angle of between 15/sup 0/ and 55/sup 0/; means defining said combustion chamber having means defining a plurality of axial hot gas flow paths from a downstream portion of the combustion chamber to flow hot gases into an upstream portion of the combustion chamber, and means for diverting some of the hot gas flow along paths in a direction circumferentially of the combustion chamber, with the latter paths being immersed in the water flow path thereby to improve heat transfer and terminating in a gas outlet, the combustion chamber comprising at least one modular element, joined axially to the frustro-conical cover and coaxial therewith. The modular element comprises an inner ring and means of defining the circumferential, radial, and spiral flow paths of the hot gases.

  1. Application of newly developed heat resistant materials for USC boilers

    International Nuclear Information System (INIS)

    This paper describes the research on the development and improvement of new high strength heat resistant steels such as SUPER304H (18Cr-9Ni-3Cu-Nb-N), NF709 (20Cr-25Ni-1.5Mo-Nb-Ti-N) and HR3C (25Cr-20Ni-Nb-N) as boiler tube, and NF616 (9Cr-0.5Mo-1.8W-Nb-V) and HCM12A (11Cr-0.4Mo-2W-Nb-V-Cu) as thick section pipe. The latest manufacturing techniques applied for these steels are introduced. In addition the high temperature strength of Alloy617 (52Ni-22Cr-13Co-9Mo-Ti-Al) that is one of the candidate materials for the next generation 700 □ USC boilers is described. (orig.)

  2. Release of Corrosive Species above the Grate in a Waste Boiler and the Implication for Improved Electrical Efficiency

    DEFF Research Database (Denmark)

    Bøjer, Martin; Jensen, Peter Arendt; Dam-Johansen, Kim;

    2010-01-01

    A relatively low electrical efficiency of 20−25% is obtained in typical west European waste boilers. Ash species released from the grate combustion zone form boiler deposits with high concentrations of Cl, Na, K, Zn, Pb, and S that cause corrosion of superheater tubes at high temperature. The...... superheater steam temperature has to be limited to around 425 °C, and thereby, the electrical efficiency remains low compared to wood or coal-fired boilers. If a separate part of the flue gas from the grate has a low content of corrosive species, it may be used to superheat steam to a higher temperature, and...

  3. Multi-unit shutdown due to boiler feedwater chemical excursion

    International Nuclear Information System (INIS)

    Ontario Hydro's Bruce Nuclear Generating Station 'B' consists of four 935 W CANDU units located on the east shore of Lake Huron in the province of Ontario, Canada. On July 25 and 26, 1989 three of the four operating units were shutdown due to boiler feedwater chemical excursions initiated by a process upset in the Water Treatment Plant that provides demineralized make-up water to all four units. The chemicals that escaped from an ion exchange vessel during a routine regeneration very quickly spread through the condensate make-up system and into the boiler feedwater systems. This resulted in boiler sulfate levels exceeding shutdown limits. A total of 260 GWH of electrical generation was unexpectedly made unavailable to the grid at a time of peak seasonal demand. This event exposed several unforeseen deficiencies and vulnerabilities in the automatic demineralized water make-up quality protection scheme, system designs, operating procedures and the ability of operating personnel to recognize and appropriately respond to such an event. The combination of these factors contributed towards turning a minor system upset into a major multi-unit shutdown. This paper provides the details of the actual event initiation in the Water Treatment Plant and describes the sequence of events that led to the eventual shutdown of three units and near shutdown of the fourth. The design inadequacies, procedural deficiencies and operating personnel responses and difficulties are described. The process of recovering from this event, the flushing out of system piping, boilers and the feedwater train is covered as well as our experiences with setting up supplemental demineralized water supplies including trucking in water and the use of rental trailer mounted demineralizing systems. System design, procedural and operational changes that have been made and that are still being worked on in response to this event are described. The latest evidence of the effect of this event on boiler tube

  4. Failures modes in model feedwater heater tubing

    International Nuclear Information System (INIS)

    Steam extracted from the turbine is used to preheat the boiler feedwater in fossil-fuel-fired steam plants in order to improve thermal efficiency. This is accomplished in a series of heaters between the condenser hot well and the boiler. The heaters usually consist of a shell containing a bundle of U-bend tubes through which the feedwater is circulated. The heaters closest to the boiler handle water at high pressure and temperature. Because of the severe service conditions, high-pressure feedwater heaters are frequently tubed with drawn-and-stress relieved Monel 400, a nickel-base alloy containing 35 percent copper. As part of a study designed to reduce the rate of tube failure in high-pressure feedwater heaters, a number of failed drawn-and-stress-relieved Monel 400 U-bend tubes removed from three high-pressure feedwater heaters were examined at Battelle to determine the causes of failure. The results of this examination are described

  5. 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.

  6. 10 CFR 431.82 - Definitions concerning commercial packaged boilers.

    Science.gov (United States)

    2010-01-01

    ... pressure boiler means a packaged boiler that is: (1) A steam boiler designed to operate at a steam pressure... steam boiler designed to operate at or below a steam pressure of 15 psig; or (2) A hot water boiler... efficiency for a commercial packaged boiler is determined using test procedures prescribed under § 431.86...

  7. PREDICTION OF OXIDE SCALE EXFOLIATION IN STEAM TUBES

    Energy Technology Data Exchange (ETDEWEB)

    Sabau, Adrian S [ORNL; Wright, Ian G [ORNL

    2010-01-01

    Numerical simulation results are presented for the prediction of the likelihood of oxide scale exfoliation from superheater tubes. The scenarios considered involved alloys T22, TP347H, and TP347HFG subjected to a simplified operating cycle in a power plant generating supercritical steam. The states of stress and strain of the oxides grown in steam were based solely on modeling the various phenomena experienced by superheater tubes during boiler operation, current understanding of the oxidation behavior of each alloy in steam, and consideration of operating parameters such as heat flux, tube dimensions, and boiler duty cycle. Interpretation of the evolution of strain in these scales, and the approach to conditions where scale failure (hence exfoliation) is expected, makes use of the type of Exfoliation Diagrams that incorporate various cracking and exfoliation criteria appropriate for the system considered. In these diagrams, the strain accumulation with time in an oxide is represented by a strain trajectory derived from the net strain resulting from oxide growth, differences in coefficients of thermal expansion among the components, and relaxation due to creep. It was found that an oxide growing on a tube subjected to routine boiler load cycling conditions attained relatively low values of net strain, indicating that oxide failure would not be expected to occur during normal boiler operation. However, during a boiler shut-down event, strains sufficient to exceed the scale failure criteria were developed after times reasonably in accord with plant experience, with the scales on the ferritic steel failing in tension, and those on the austenitic steels in compression. The results presented illustrate that using this approach to track the state of strain in the oxide scale through all phases of boiler operation, including transitions from full-to-low load and shut-down events, offers the possibility of identifying the phase(s) of boiler operation during which oxide

  8. 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... Steam Gauges § 230.47 Boiler number. (a) Generally. The builder's number of the boiler, if known, shall be stamped on the steam dome or manhole flange. If the builder's number cannot be obtained,...

  9. 29 CFR 1915.162 - Ship's boilers.

    Science.gov (United States)

    2010-07-01

    ... Ship's boilers. (a) Before work is performed in the fire, steam, or water spaces of a boiler where employees may be subject to injury from the direct escape of a high temperature medium such as steam, or... dead boiler with the live system or systems shall be secured, blanked, and tagged indicating...

  10. Sootblowing optimization for improved boiler performance

    Science.gov (United States)

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

    2013-07-30

    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.

  11. Sootblowing optimization for improved boiler performance

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. Superheater materials for waste incinerator boilers. Trials at the Hoegdalen plant

    International Nuclear Information System (INIS)

    In order to obtain an acceptable length of life for the superheaters in waste incinerated boilers a considerably lower steam temperature is used than when incinerating conventional fuel. In spite of this the life of the superheaters is unsatisfactory, with the occurrence of damage in some type of incinerator boilers after only a few years operation. The use of high alloyed material instead of conventional pressure vessel steels can increase the length of life and improve operational efficiency in existing incinerator boilers. Such tubes permit higher steam data for new plants. Cooled materials testing probes have been mounted in the flue gas duct close to the superheater in two boilers in the Hoegdalen plant, Stockholm. The materials temperatures have been maintained in the range 400-500 degrees C. Low metal losses have been obtained, in particular with Alloy 625, but also with Alloy 825 and Sandvik Sanicro 28. The attack on the tubes is corrosion, caused by the aggressive dust which is trapped in the superheaters. In these trials it has been shown that correct boiler design is very important, in conjunction with the choice of materials

  13. Dynamic simulation model for ultra supercritical 1 000 MW unit boilers%Dynamic simulation model for ultra supercritical 1000 MW unit boilers

    Institute of Scientific and Technical Information of China (English)

    XU Hui; XU Ershu

    2013-01-01

    On the basis of heat transfer characteristics of working fluid at different pressures inside the water wall tube and structure of the ultra supercritical 1 000 MW unit once through boiler in Jianbi Power Plant,the varying phase transformation point method was adopted to establish the moving-boundary dynamic simulation model of water wall in ultra supercritical once through boilers,especially the length variation of hot water section,evaporation section and superheat section against the load changing.On this basis,the real-time dynamic simulation model for ultra-supercritical 1 000 MW unit boiler in Jianbi Power Plant was built on the STAR-90 simulation platform.The dynamic and static characteristics test showed that,this model can simulate the unit's startup/shutdown process and some typical fault conditions accurately,and had good dynamic and static performance.

  14. High-Temperature Behavior of a NiCr-Coated T91 Boiler Steel in the Platen Superheater of Coal-Fired Boiler

    Science.gov (United States)

    Chatha, Sukhpal Singh; Sidhu, Hazoor S.; Sidhu, Buta S.

    2013-06-01

    Ni-20Cr coating was deposited on T91 boiler tube steel by high-velocity oxy-fuel (HVOF) process to enhance high-temperature oxidation resistance. High-temperature performance of bare, as well as HVOF-coated steel specimens was evaluated for 1500 h under in the platen superheater zone of coal-fired boiler, where the temperature was around 900 °C. Experiments were carried out for 15 cycles, each of 100-h duration followed by 1-h cooling at ambient temperature. The extent of degradation of the specimens was assessed by the thickness loss and depth of internal corrosion attack. Ni-20Cr-coated steel performed better than the uncoated steel in actual boiler environment. The improved degradation resistance of Ni-20Cr coating can be attributed to the presence of Cr2O3 in the top oxide scale and dense microstructure.

  15. 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.

  16. Hydrodynamic analysis and calculation of metal temperature distribution in spiral water wall of ultra supercritical tower boiler

    Science.gov (United States)

    Shen, Chengwu; Yang, Dong; Yao, Danhua; Zhu, Yufeng; Xu, Xueyuan

    2013-07-01

    In this paper, the spiral water wall system of a 1000MW ultra supercritical tower boiler is simplified as a network system, consisting of circuits, pressure grids and connecting tubes. The establishment of the mathematical model for calculating the mass flux distribution and metal temperature in water wall is based on the mass, momentum and energy conservation equations. The water wall flow distribution and temperature profile of the boiler were computed. The result shows that the differences of outlet temperature and mass flux are small in spiral tube water wall at BMCR, 75%BMCR load and 40%BMCR load. The metal temperatures are all in the allowable ranger.

  17. Integrating multi-objective optimization with computational fluid dynamics to optimize boiler combustion process of a coal fired power plant

    International Nuclear Information System (INIS)

    Highlights: • A coal fired power plant boiler combustion process model based on real data. • We propose multi-objective optimization with CFD to optimize boiler combustion. • The proposed method uses software CORBA C++ and ANSYS Fluent 14.5 with AI. • It optimizes heat flux transfers and maintains temperature to avoid ash melt. - Abstract: The dominant role of electricity generation and environment consideration have placed strong requirements on coal fired power plants, requiring them to improve boiler combustion efficiency and decrease carbon emission. Although neural network based optimization strategies are often applied to improve the coal fired power plant boiler efficiency, they are limited by some combustion related problems such as slagging. Slagging can seriously influence heat transfer rate and decrease the boiler efficiency. In addition, it is difficult to measure slag build-up. The lack of measurement for slagging can restrict conventional neural network based coal fired boiler optimization, because no data can be used to train the neural network. This paper proposes a novel method of integrating non-dominated sorting genetic algorithm (NSGA II) based multi-objective optimization with computational fluid dynamics (CFD) to decrease or even avoid slagging inside a coal fired boiler furnace and improve boiler combustion efficiency. Compared with conventional neural network based boiler optimization methods, the method developed in the work can control and optimize the fields of flue gas properties such as temperature field inside a boiler by adjusting the temperature and velocity of primary and secondary air in coal fired power plant boiler control systems. The temperature in the vicinity of water wall tubes of a boiler can be maintained within the ash melting temperature limit. The incoming ash particles cannot melt and bond to surface of heat transfer equipment of a boiler. So the trend of slagging inside furnace is controlled. Furthermore, the

  18. Adaptive controlling of power boiler

    OpenAIRE

    Wojcik, W.; Kalita, M; Smolarz, A.

    2004-01-01

    This paper presents research on adaptive control (AC) of combastion process in in¬dustry. Results were obtained from research conducted in laboratory combustion chamber with usage of Fiber Optical Measurement System (FOMS) with electronic block. Simulation proved that implementing AC and FOMS to burning process improves flue gasses parameters -direct measure of power boiler ecologic and economical quality of work.

  19. Test results from a full-scale sodium reflux pool-boiler solar receiver

    Science.gov (United States)

    Moreno, J. B.; Andraka, C. E.; Diver, R. B.; Ginn, W. C.; Dudley, V.; Rawlinson, K. S.

    1990-01-01

    A sodium reflux pool-boiler solar receiver has been tested on a nominal 75 kW sub t parabolic-dish concentrator. The purpose was to demonstrate the feasibility of reflux-receiver technology for application to Stirling-engine dish-electric systems. In this application, pool boilers (and more generally liquid-metal reflux receivers) have a number of advantages over directly-illuminated tube receivers. The advantages, to be discussed, include more uniform temperature, which results in longer lifetime and higher temperature available to the engine.

  20. Study and design of platen superheater of 300 MW CFB boiler

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Man; Lv, Qinggang; Sun, Yunkai [Chinese Academy of Sciences, Beijing (China). Inst. of Engineering Thermophysics; Jiang, Xiaoguo [Harbin Boiler Company Limited, Harbin (China)

    2013-07-01

    In order to avoid overtemperature tube explosion of the platen superheater, the measurements of metal temperatures and the heat transfer coefficients of the platen superheater in a commercial 300 MW Circulating Fluidized Bed (CFB) boiler are conducted in this work. The measured data is analyzed and the theoretical calculation is made. On the basis, the reasonable steam flow path and the value range of heat transfer coefficient of the middle temperature platen superheater are applied for design. Furthermore, based on operation experience from several 300 MW CFB boilers, a design principle of the mass velocity and the arrangement of the platen superheater in the furnace is given.

  1. Developing Boiler Concepts as Integrated Units

    DEFF Research Database (Denmark)

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

    2004-01-01

    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...... bricks in the boiler concept to each other and hereby obtain signicant reductions in the boiler concepts weight and foot-print . The actual development project has focused on an heavy fuel oil-red boiler for the marine market with a capacity in the range 1-10 t/h saturated steam. The development project...

  2. Computational Modeling and Assessment Of Nanocoatings for Ultra Supercritical Boilers

    Energy Technology Data Exchange (ETDEWEB)

    David W. Gandy; John P. Shingledecker

    2011-04-11

    Forced outages and boiler unavailability in conventional coal-fired fossil power plants is most often caused by fireside corrosion of boiler waterwalls. Industry-wide, the rate of wall thickness corrosion wastage of fireside waterwalls in fossil-fired boilers has been of concern for many years. It is significant that the introduction of nitrogen oxide (NOx) emission controls with staged burners systems has increased reported waterwall wastage rates to as much as 120 mils (3 mm) per year. Moreover, the reducing environment produced by the low-NOx combustion process is the primary cause of accelerated corrosion rates of waterwall tubes made of carbon and low alloy steels. Improved coatings, such as the MCrAl nanocoatings evaluated here (where M is Fe, Ni, and Co), are needed to reduce/eliminate waterwall damage in subcritical, supercritical, and ultra-supercritical (USC) boilers. The first two tasks of this six-task project-jointly sponsored by EPRI and the U.S. Department of Energy (DE-FC26-07NT43096)-have focused on computational modeling of an advanced MCrAl nanocoating system and evaluation of two nanocrystalline (iron and nickel base) coatings, which will significantly improve the corrosion and erosion performance of tubing used in USC boilers. The computational model results showed that about 40 wt.% is required in Fe based nanocrystalline coatings for long-term durability, leading to a coating composition of Fe-25Cr-40Ni-10 wt.% Al. In addition, the long term thermal exposure test results further showed accelerated inward diffusion of Al from the nanocrystalline coatings into the substrate. In order to enhance the durability of these coatings, it is necessary to develop a diffusion barrier interlayer coating such TiN and/or AlN. The third task 'Process Advanced MCrAl Nanocoating Systems' of the six-task project jointly sponsored by the Electric Power Research Institute, EPRI and the U.S. Department of Energy (DE-FC26-07NT43096)- has focused on

  3. 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)

    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

  4. Predictive modelling of boiler fouling. Final report.

    Energy Technology Data Exchange (ETDEWEB)

    Chatwani, A

    1990-12-31

    A spectral element method embodying Large Eddy Simulation based on Re- Normalization Group theory for simulating Sub Grid Scale viscosity was chosen for this work. This method is embodied in a computer code called NEKTON. NEKTON solves the unsteady, 2D or 3D,incompressible Navier Stokes equations by a spectral element method. The code was later extended to include the variable density and multiple reactive species effects at low Mach numbers, and to compute transport of large particles governed by inertia. Transport of small particles is computed by treating them as trace species. Code computations were performed for a number of test conditions typical of flow past a deep tube bank in a boiler. Results indicate qualitatively correct behavior. Predictions of deposition rates and deposit shape evolution also show correct qualitative behavior. These simulations are the first attempts to compute flow field results at realistic flow Reynolds numbers of the order of 10{sup 4}. Code validation was not done; comparison with experiment also could not be made as many phenomenological model parameters, e.g., sticking or erosion probabilities and their dependence on experimental conditions were not known. The predictions however demonstrate the capability to predict fouling from first principles. Further work is needed: use of large or massively parallel machine; code validation; parametric studies, etc.

  5. Experimental Study on Heat Transfer Characteristics of Shell and Tube Heat Exchanger Using Hitran Wire Matrix Turbulators As Tube Inserts.

    OpenAIRE

    Manoj; A.M.Mulla

    2014-01-01

    Shell and tube heat exchangers are extensively used in boilers, oil coolers, pre-heaters, condensers etc. They are also having special importance in process application as well as refrigeration and air conditioning industries. The present paper emphasizes on heat transfer characteristics of shell and tube heat exchangers with the aid of hiTRAN wire matrix inserts is been studied. Investigations were made on effect of mass flow rate of water on heat transfer characteristics in ...

  6. 46 CFR 52.05-45 - Circumferential joints in pipes, tubes and headers (modifies PW-41).

    Science.gov (United States)

    2010-10-01

    ..., tubes and headers shall be as required by PW-41 of section I of the ASME Boiler and Pressure Vessel Code (incorporated by reference; see 46 CFR 52.01-1) except as noted otherwise in this section. (b) (Modifies PW-41.1) Circumferential welded joints in pipes, tubes, and headers of pipe material must be nondestructively examined...

  7. Final Report, Materials for Industrial Heat Recovery Systems, Tasks 3 and 4 Materials for Heat Recovery in Recovery Boilers

    Energy Technology Data Exchange (ETDEWEB)

    Keiser, James R.; Kish, Joseph R.; Singh, Preet M.; Sarma, Gorti B.; Yuan, Jerry; Gorog, J. Peter; Frederick, Laurie A.; Jette, Francois R.; Meisner, Roberta A.; Singbeil, Douglas L.

    2007-12-31

    The DOE-funded project on materials for industrial heat recovery systems included four research tasks: materials for aluminum melting furnace recuperator tubes, materials and operational changes to prevent cracking and corrosion of the co-extruded tubes that form primary air ports in black liquor recovery boilers, the cause of and means to prevent corrosion of carbon steel tubes in the mid-furnace area of recovery boilers, and materials and operational changes to prevent corrosion and cracking of recovery boiler superheater tubes. Results from studies on the latter two topics are given in this report while separate reports on results for the first two tasks have already been published. Accelerated, localized corrosion has been observed in the mid-furnace area of kraft recovery boilers. This corrosion of the carbon steel waterwall tubes is typically observed in the vicinity of the upper level of air ports where the stainless clad co-extruded wall tubes used in the lower portion of the boiler are welded to the carbon steel tubes that extend from this transition point or “cut line” to the top of the boiler. Corrosion patterns generally vary from one boiler to another depending on boiler design and operating parameters, but the corrosion is almost always found within a few meters of the cut line and often much closer than that. This localized corrosion results in tube wall thinning that can reach the level where the integrity of the tube is at risk. Collection and analysis of gas samples from various areas near the waterwall surface showed reducing and sulfidizing gases were present in the areas where corrosion was accelerated. However, collection of samples from the same areas at intervals over a two year period showed the gaseous environment in the mid-furnace section can cycle between oxidizing and reducing conditions. These fluctuations are thought to be due to gas flow instabilities and they result in an unstable or a less protective scale on the carbon steel

  8. Development of Erosion-Corrosion-Resistant Cold-Spray Nanostructured Ni-20Cr Coating for Coal-Fired Boiler Applications

    Science.gov (United States)

    Kumar, M.; Singh, H.; Singh, N.; Chavan, N. M.; Kumar, S.; Joshi, S. V.

    2015-12-01

    The erosion-corrosion (E-C) behavior of a cold-spray nanostructured Ni-20Cr coating was studied under cyclic conditions in a coal-fired boiler. This study was done for 15 cycles (1500 h), in which each cycle comprised 100 h of heating in the boiler environment, followed by 1 h of cooling under ambient air conditions. The E-C extent was evaluated in terms of thickness loss data of the samples. The eroded-corroded samples were characterized using XRD, SEM/EDS, and x-ray mapping analyses. The nanostructured coating offered excellent E-C protection to boiler tube material (SA 516 steel) under harsh live conditions of the boiler. This E-C resistance offered by investigated coating may be attributed to the presence of protective NiO and Cr2O3 phases in its oxide scale and its superior as-sprayed microhardness.

  9. High Temperature Corrosion Problem of Boiler Components in presence of Sulfur and Alkali based Fuels

    Science.gov (United States)

    Ghosh, Debashis; Mitra, Swapan Kumar

    2011-04-01

    Material degradation and ageing is of particular concern for fossil fuel fired power plant components. New techniques/approaches have been explored in recent years for Residual Life assessment of aged components and material degradation due to different damage mechanism like creep, fatigue, corrosion and erosion etc. Apart from the creep, the high temperature corrosion problem in a fossil fuel fired boiler is a matter of great concern if the fuel contains sulfur, chlorine sodium, potassium and vanadium etc. This paper discusses the material degradation due to high temperature corrosion in different critical components of boiler like water wall, superheater and reheater tubes and also remedial measures to avoid the premature failure. This paper also high lights the Residual Life Assessment (RLA) methodology of the components based on high temperature fireside corrosion. of different critical components of boiler.

  10. Nature of fireside deposits in a bagasse and groundnut shell fired 20 MW thermal boiler

    International Nuclear Information System (INIS)

    The nature of deposit formation on the fireside surfaces of the boiler tubes in the various parts (water walls, platen superheater, final superheater, economizer, electrostatic precipitator etc.) of a commercial 20 MW stoker-fired boiler being fired with a mixture of 80% bagasse and 20% groundnut shell has been analyzed. The deposits in the various portions of the boiler were characterized by particle size analysis, chemical analysis, X-ray diffraction and scanning electron microscopy. The deposits were found to be mainly quartz, alkali and alkaline earth silicates and sulfates. From the phase constitution and other microscopic characteristics of the deposit, it can be inferred that the silicates in the deposit formed through inertial impaction and the sulfates formed by vapor phase deposition

  11. Improved Materials for Use as Components in Kraft Black Liquor Recovery Boilers; TOPICAL

    International Nuclear Information System (INIS)

    This Cooperative Research and Development Agreement (CRADA) was undertaken to evaluate current and improved materials and materials processing conditions for use as components in kraft black liquor recovery boilers and other unit processes. The main areas addressed were: (1) Improved Black Liquor Nozzles, (2) Weld Overlay of Composite Floor Tubes, and (3) Materials for Lime Kilns. Iron aluminide was evaluated as an alternate material for the nozzles used to inject an aqueous solution known as black liquor into recovery boilers as well for the uncooled lining in the ports used for the nozzles. Although iron aluminide is known to have much better sulfidation resistance in gases than low alloy and stainless steels, it did not perform adequately in the environment where it came into contact with molten carbonate, sulfide and sulfate salts. Weld overlaying carbon steel tubes with a layer of stainless weld metal was a proposed method of extending the life of recovery boiler floor tubes that have experienced considerable fireside corrosion. After exposure under service conditions, sections of weld overlaid floor tubes were removed from a boiler floor and examined metallographically. Examination results indicated satisfactory performance of the tubes. Refractory-lined lime kilns are a critical component of the recovery process in kraft pulp mills, and the integrity of the lining is essential to the successful operation of the kiln. A modeling study was performed to determine the cause of, and possible solutions for, the repeated loss of the refractory lining from the cooled end of a particular kiln. The evaluation showed that the temperature, the brick shape and the coefficient of friction between the bricks were the most important parameters influencing the behavior of the refractory lining

  12. Evaluation of tube shielding; Utvaerdering av tubskyddsmaterial

    Energy Technology Data Exchange (ETDEWEB)

    Hjoernhede, Anders; Westberg, Stig-Bjoern; Henderson, Pamela; Wetterstroem, Jonas; Jonasson, Anna

    2007-12-15

    Problems with soot-blowing have increased recently because of the poor fuel quality. Studies show that removing all the deposit by soot-blowing increases the metal loss of the superheaters, which drastically shortens component lifetimes. A simple, effective and common way of increasing the lifetime is to use tube shielding. Austenitic stainless steels seem to be the type of material most commonly used for tube shielding. It is thought that they give better protection against material removal than ferritic steels, but the cost of austenitics is several times greater than ferritic steels. It is clear that there is a significant economic advantage in choosing the right material for tube shielding, even though it might be expected that the cheaper materials do not perform as well as the more expensive ones. The reason for the study reported here is that very little material data exists in the literature. Few, if any tests have been performed to study the choice of material for tube shielding. The goal was to compare and evaluate a number of materials in a boiler to see if it is possible to replace the shielding material presently used with cheaper alternatives. About a dozen different shielding materials were installed and exposed for 4000 hours on primary- and secondary superheaters in a waste-fired boiler in Norrkoeping (Haendeloe Boiler 14.75MW). In total, 130 m of test material were installed and measured in several positions: a least 150 thickness measurements, before and after, were made on every tube shield. The results showed that the greatest attack was found on the secondary superheater shielding, where both the gas- and steam temperatures were higher. When considering cost and lifetime Sicromal 10 and 12 (however not Sicromal 8) and 15Mo3 are recommended as being better than 253 MA. The results should be of interest to most plants firing biomass or waste

  13. CFD Simulation On CFBC Boiler

    OpenAIRE

    Amol S. Kinkar; G. M. Dhote; R.R. Chokkar

    2015-01-01

    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...

  14. Scandinavian baffle boiler design revisited

    OpenAIRE

    Stepanov Borivoj Lj.; Pešenjanski Ivan K.; Spasojević Momčilo Đ.

    2015-01-01

    The aim of this paper is to examine whether the use of baffles in a combustion chamber, one of the well-known low-cost methods for the boiler performance improvement, can be enhanced. Modern day tools like computational fluid dynamics were not present at the time when these measures were invented, developed and successfully applied. The objective of this study is to determine the influence of location and length of a baffle in a furnace, for different mass ...

  15. 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)

  16. 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)

  17. High Temperature Behavior of Cr3C2-NiCr Coatings in the Actual Coal-Fired Boiler Environment

    Science.gov (United States)

    Bhatia, Rakesh; Sidhu, Hazoor Singh; Sidhu, Buta Singh

    2015-03-01

    Erosion-corrosion is a serious problem observed in steam-powered electricity generation plants, and industrial waste incinerators. In the present study, four compositions of Cr3C2-(Ni-20Cr) alloy coating powder were deposited by high-velocity oxy-fuel spray technique on T-91 boiler tube steel. The cyclic studies were performed in a coal-fired boiler at 1123 K ± 10 K (850 °C ± 10 °C). X-ray diffraction, scanning electron microscopy/energy dispersive X-ray analysis and elemental mapping analysis techniques were used to analyze the corrosion products. All the coatings deposited on T-91 boiler tube steel imparted hot corrosion resistance. The 65 pctCr3C2 -35 pct (Ni-20Cr)-coated T-91 steel sample performed better than all other coated samples in the given environment.

  18. Business opportunities in boiler control systems

    Energy Technology Data Exchange (ETDEWEB)

    McHale, A.P.

    1988-03-01

    Each year some Pound 4.5 billion is spent on fuel to fire the UK non-domestic boiler stock. The average age of the 500 000 population of boilers is more than 10 years and in that time great advances have been made in the capacity and capability of microprocessor controls. There is undoubtedly an enormous potential to retrofit existing boilers with the latest controls both to improve efficiency of production and utilisation.

  19. Boiler plants completed in record time

    International Nuclear Information System (INIS)

    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

  20. Gastrostomy Tube (G-Tube)

    Science.gov (United States)

    ... endoscope (a thin, flexible tube with a tiny camera and light at the tip) inserted through the ... Nemours Foundation, iStock, Getty Images, Corbis, Veer, Science Photo Library, Science Source Images, Shutterstock, and Clipart.com

  1. 49 CFR 230.30 - Lap-joint seam boilers.

    Science.gov (United States)

    2010-10-01

    ..., 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...

  2. Particulate emission factor: A case study of a palm oil mill boiler

    International Nuclear Information System (INIS)

    A study to investigate the particulate emission from a boiler of a palm oil mill plant equipped with a multi-cyclones particulate arrest or was performed and reported in this paper. The particulate emission concentration was measured at the outlet of a 8 mt/ hr capacity water-tube typed boiler of a palm oil mill plant processing 27mt/ hr of fresh fruit bunch (FFB). The particulate sample was collected iso-kinetically using the USEPA method 5 sampling train through a sampling port made at the duct of the exiting flue gas between the boiler and a multi-cyclones unit. Results showed that the particulate emission rates exiting the boiler varied from 0.09 to 0.60 g/s with an average of 0.29 + 0.18 g/ s. While the average particulate emission concentration exiting the boiler was 12.1 + 7.36 g/ Nm3 (corrected to 7 % oxygen concentration), ranging from 3.62 to 25.3 g/ Nm3 (at 7 % O2) of the flue gas during the measurement. Based on the 27 mt/ hr FFB processed and the capacity of the boiler of 8mt steam/ hr, the calculated particulate emission factor was 39 g particulate/ mt FFB processed or 131 g particulate/ mt boiler capacity, respectively. In addition, based on the finding and in order to comply with the emission limits of 0.4 g/ Nm3, the collection efficiency of any given particulate emission pollution control system to consider for the mill will be from 87 to 98 %, which is not easily achievable with the existing multi-cyclones unit. A considerable amount of efforts are still needed pertaining to the particulate emission control problem in the industry. (author)

  3. Ear tube insertion

    Science.gov (United States)

    Myringotomy; Tympanostomy; Ear tube surgery; Pressure equalization tubes; Ventilating tubes; Ear infection - tubes; Otitis - tubes ... trapped fluid can flow out of the middle ear. This prevents hearing loss and reduces the risk ...

  4. WASTE HEAT RECOVERY FROM BOILER OF LARGE-SCALE TEXTILE INDUSTRY

    Directory of Open Access Journals (Sweden)

    Prateep Pattanapunt

    2013-01-01

    Full Text Available Many industrial heating processes generate waste energy in textile industry; especially exhaust gas from the boiler at the same time reducing global warming. Therefore, this article will present a study the way to recovery heat waste from boiler exhaust gas by mean of shell and tube heat exchanger. Exhaust gas from boiler dyeing process, which carries a large amount of heat, energy consumptions could be decrease by using of waste-heat recovery systems. In this study, using ANASYS simulation performs a thermodynamics analysis. An energy-based approach is performed for optimizing the effective working condition for waste-heat recovery with exhaust gas to air shell and tube heat exchanger. The variations of parameters, which affect the system performance such as, exhaust gas and air temperature, velocity and mass flow rate and moisture content is examined respectively. From this study, it was found that heat exchanger could be reduced temperature of exhaust gases and emission to atmosphere and the time payback is the fastest. The payback period was determined about 6 months for investigated ANSYS. The air is circulated in four passes from the top to the bottom of the test section, in overall counter-flow with exhaust gas. The front area is 1720×1720 mm, the flow length 7500 mm, the inner and outer diameter of exhaust gas is 800 mm, the tube assembly consist of 196 tubes, the tube diameter is 76.2 mm, the tube thickness is 2.6 mm, the tube length is 4500 mm, the tube length of air inner and outer is 500 mm. The result show that, the boiler for superheated type there are exhaust gas temperature is 190°C, 24% the moisture content of fuel and there are palm kernel shell 70 tons day-1 which there are the high temperature after the heat exchanger, 150°C. It was occurred acid rain. The hot air from heat exchanger process can be reduced the moisture of palm kernel shell fuel to 15%.The fuel consumption is reduced by about 2.05% (322.72 kJ kg-1

  5. Coiled tubing

    International Nuclear Information System (INIS)

    Oil and gas wells that flow on initial completion eventually reach a condition of liquid loading that kills the wells. This results form declining reservoir pressure, decreased gas volume (velocity), increased water production and other factors that cause liquids to accumulate at the bottom of the well and exert back pressure on the formation. This restricts or in some cases prevents fluid entry into the wellbore form the formation. Flowing production can be restored or increased by reducing surface backpressure, well bore stimulation, pressure maintenance or by installing a string of smaller diameter tubing. This paper reports on installation (hanging off) of a concentric string of coiled tubing inside existing production tubing which is an economically viable, safe, convenient and effective alterative for returning some of these liquid loaded )logged-up) wells to flowing status

  6. Distributed parameter modeling and thermal analysis of a spiral water wall in a supercritical boiler

    OpenAIRE

    Zheng Shu; Luo Zixue; Zhou Huaichun

    2013-01-01

    In this paper, a distributed parameter model for the evaporation system of a supercritical spiral water wall boiler is developed based on a 3-D temperature field. The mathematical method is formulated for predicting the heat flux and the metal-surface temperature. The results show that the influence of the heat flux distribution is more obvious than that of the heat transfer coefficient distribution in the spiral water wall tube, and the peak of the heat tr...

  7. Loss of feed flow, steam generator tube rupture and steam line break thermohydraulic experiments

    International Nuclear Information System (INIS)

    The Westinghouse Model Boiler No. 2 (MB-2) steam generator test model at the Engineering Test Facility in Tampa, Florida, was reinstrumented and modified for performing a series of tests simulating steam generator accident transients. The transients simulated were: loss of feed flow, steam generator tube rupture, and steam line break events. This document presents a description of (1) the model boiler and the associated test facility, (2) the tests performed, and (3) the analyses of the test results

  8. Loss of feed flow, steam generator tube rupture and steam line break thermohydraulic experiments

    Energy Technology Data Exchange (ETDEWEB)

    Mendler, O J; Takeuchi, K; Young, M Y

    1986-10-01

    The Westinghouse Model Boiler No. 2 (MB-2) steam generator test model at the Engineering Test Facility in Tampa, Florida, was reinstrumented and modified for performing a series of tests simulating steam generator accident transients. The transients simulated were: loss of feed flow, steam generator tube rupture, and steam line break events. This document presents a description of (1) the model boiler and the associated test facility, (2) the tests performed, and (3) the analyses of the test results.

  9. 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...

  10. Seeking for total efficiency on boiler operation

    International Nuclear Information System (INIS)

    In this paper, as for the boiler in the private power generation plant which has been in operation since July, 1974 based on the production increase project of the factory, the measures for energy conservation considered from the planning and design stage, the countermeasures to the low loading of the boiler by the epoch-making effect of the energy conservation in the production system since the oil crisis in 1973, and the cost management of the boiler are described. The outline of the private power generation plant is shown. The boiler facilities are the boiler for power generation of 81 kg/cm2, 433degC, 65 t/h, the saturation boiler of 30 kg/cm2, 211degC, 47 t/h, and the waste heat boiler of 22 kg/cm2, 211 degC, 4.2 t/h. As the measures for energy conservation, tangential corner firing-two stage combustion process was adopted, and the total heat of recovered drain has been utilized. The remodeling and the effect of improvement of the boiler and the turbine as the countermeasures to low loading are reported. The examples of other energy conservation in the waste tire incinerator, air compressor, exhaust desulfurizer and air preheater are described. (K.I.)

  11. Investigations on the Behavior of HVOF and Cold Sprayed Ni-20Cr Coating on T22 Boiler Steel in Actual Boiler Environment

    Science.gov (United States)

    Bala, Niraj; Singh, Harpreet; Prakash, Satya; Karthikeyan, J.

    2012-01-01

    High temperature corrosion accompanied by erosion is a severe problem, which may result in premature failure of the boiler tubes. One countermeasure to overcome this problem is the use of thermal spray protective coatings. In the current investigation high velocity oxy-fuel (HVOF) and cold spray processes have been used to deposit commercial Ni-20Cr powder on T22 boiler steel. To evaluate the performance of the coatings in actual conditions the bare as well as the coated steels were subjected to cyclic exposures, in the superheater zone of a coal fired boiler for 15 cycles. The weight change and thickness loss data were used to establish kinetics of the erosion-corrosion. X-ray diffraction, surface and cross-sectional field emission scanning electron microscope/energy dispersive spectroscopy (FE-SEM/EDS) and x-ray mapping techniques were used to analyse the as-sprayed and corroded specimens. The HVOF sprayed coating performed better than its cold sprayed counterpart in actual boiler environment.

  12. Steam generator chemical cleaning demonstration test No. 1 in a pot boiler

    International Nuclear Information System (INIS)

    The effectiveness of the Electric Power Research Institute (EPRI Mark I) chemical cleaning solvent process was tested utilizing a 12 tube pot boiler that had previously been fouled and dented under 30 days of high chloride fault chemistry operation. Specifically, the intent of this chemical cleaning test was to: (1) dissolve sludge from the tubesheet, (2) remove non-protective magnetite from dented tube/support crevice regions, and (3) quantify the extent of corrosion of steam generator material during the test. Two laboratory cleaning demonstrations of 191 and 142 hours were performed

  13. Ear Tubes

    Science.gov (United States)

    ... of the ear drum or eustachian tube, Down Syndrome, cleft palate, and barotrauma (injury to the middle ear caused by a reduction of air pressure, ... specialist) may be warranted if you or your child has experienced repeated ... fluid in the middle ear, barotrauma, or have an anatomic abnormality that ...

  14. Optimizing the integrated design of boilers - simulation

    DEFF Research Database (Denmark)

    Sørensen, Kim; Karstensen, Claus M. S.; Condra, Thomas Joseph;

    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...... important to see the 3 components as an integrated unit and optimize these as such. This means that the burner must be designed and optimized exactly to the pressure part where it is utilized, the control system must have a conguration optimal for the pressure part and burner where it is utilized etc....... Traditionally boiler control systems have been designed in a rather simple manner consisting of a feed water controller and a pressure controller; two controllers which, in principle, operated without any interaction - for more details on boiler control see [4]. During the last year Aalborg Industries A/S has...

  15. PAH emission from the industrial boilers.

    Science.gov (United States)

    Li, C; Mi, H; Lee, W; You, W; Wang, Y

    1999-10-01

    Polycyclic aromatic hydrocarbons (PAHs) emitted from 25 industrial boilers were investigated. The fuels used for these 25 boilers included 21 heavy oil, two diesel, a co-combustion of heavy oil and natural gas (HO+NG) and a co-combustion of coke oven gas and blast furnace gas (COG+BFG) boilers. PAH samples from the stack flue gas (gas and particle phases) of these 25 boilers were collected by using a PAH stack sampling system. Twenty one individual PAHs were analyzed primarily by a gas chromatography/mass spectrometer (GC/MS). Total-PAH concentration in the flue gas of 83 measured data for these 25 boiler stacks ranged between 29.0 and 4250 microg/m(3) and averaged 488 microg/m(3). The average of PAH-homologue mass (F%) counted for the total-PAH mass was 54.7%, 9.47% and 15.3% for the 2-ring, 3-ring and 4-ring PAHs, respectively. The PAHs in the stack flue gas were dominant in the lower molecular weight PAHs. The emission factors (EFs) of total-PAHs were 13,300, 2920, 2880 and 208 microg/kg-fuel for the heavy oil, diesel, HO+NG and COG+BFG fueled-boiler, respectively. Nap was the most predominant PAH occurring in the stack flue gas. In addition, the EF of 21 individual PAHs in heavy-oil boiler were almost the highest among the four various fueled-boilers except for those of FL and BkF in the diesel boiler. Furthermore, the EF of total-PAHs or BaP for heavy oil were both one order of magnitude higher than that for the diesel-fueled boiler. PMID:10502602

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

    International Nuclear Information System (INIS)

    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

  17. NOx Control Options and Integration for US Coal Fired Boilers

    Energy Technology Data Exchange (ETDEWEB)

    Mike Bockelie; Kevin Davis; Temi Linjewile; Connie Senior; Eric Eddings; Kevin Whitty; Larry Baxter; Calvin Bartholomew; William Hecker; Stan Harding; Robert Hurt

    2003-12-31

    This is the fourteenth Quarterly Technical Report for DOE Cooperative Agreement No: DEFC26-00NT40753. The goal of the project is 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) is providing co-funding for this program. Using the initial CFD baseline modeling of the Gavin Station and the plant corrosion maps, six boiler locations for the corrosion probes were identified and access ports have been installed. Preliminary corrosion data obtained appear consistent and believable. In situ, spectroscopic experiments at BYU reported in part last quarter were completed. New reactor tubes have been made for BYU's CCR that allow for testing smaller amounts of catalyst and thus increasing space velocity; monolith catalysts have been cut and a small reactor that can accommodate these pieces for testing is in its final stages of construction. A poisoning study on Ca-poisoned catalysts was begun this quarter. A possible site for a biomass co-firing test of the slipstream reactor was visited this quarter. The slipstream reactor at Rockport required repair and refurbishment, and will be re-started in the next quarter. This report describes the final results of an experimental project at Brown University on the fundamentals of ammonia / fly ash interactions with relevance to the operation of advanced NOx control technologies such as selective catalytic reduction. The Brown task focused on the measurement of ammonia adsorption isotherms on commercial fly ash samples subjected to a variety of treatments and on the chemistry of dry and semi-dry ammonia removal processes.

  18. Slagging behavior of upgraded brown coal and bituminous coal in 145 MW practical coal combustion boiler

    Energy Technology Data Exchange (ETDEWEB)

    Akiyama, Katsuya; Pak, Haeyang; Takubo, Yoji [Kobe Steel, Ltd, Kobe (Japan). Mechanical Engineering Research Lab.; Tada, Toshiya [Kobe Steel, Ltd, Takasago (Japan). Coal and Energy Technology Dept.; Ueki, Yasuaki [Nagoya Univ. (Japan). Energy Science Div.; Yoshiie, Ryo; Naruse, Ichiro [Nagoya Univ. (Japan). Dept. of Mechanical Science and Engineering

    2013-07-01

    The purpose of this study is to quantitatively evaluate behaviors of ash deposition during combustion of Upgraded Brown Coal (UBC) and bituminous coal in a 145 MW practical coal combustion boiler. A blended coal consisting 20 wt% of the UBC and 80 wt% of the bituminous coal was burned for the combustion tests. Before the actual ash deposition tests, the molten slag fractions of ash calculated by chemical equilibrium calculations under the combustion condition was adopted as one of the indices to estimate the tendency of ash deposition. The calculation results showed that the molten slag fraction for UBC ash reached approximately 90% at 1,523 K. However, that for the blended coal ash became about 50%. These calculation results mean that blending the UBC with a bituminous coal played a role in decreasing the molten slag fraction. Next, the ash deposition tests were conducted, using a practical pulverized coal combustion boiler. A water-cooled stainless-steel tube was inserted in locations at 1,523 K in the boiler to measure the amount of ash deposits. The results showed that the mass of deposited ash for the blended coal increased and shape of the deposited ash particles on the tube became large and spherical. This is because the molten slag fraction in ash for the blended coal at 1,523 K increased and the surface of deposited ash became sticky. However, the mass of the deposited ash for the blended coal did not greatly increase and no slagging problems occurred for 8 days of boiler operation under the present blending conditions. Therefore, appropriate blending of the UBC with a bituminous coal enables the UBC to be used with a low ash melting point without any ash deposition problems in a practical boiler.

  19. Electron tube

    Energy Technology Data Exchange (ETDEWEB)

    Suyama, Motohiro (Hamamatsu, JP); Fukasawa, Atsuhito (Hamamatsu, JP); Arisaka, Katsushi (Los Angeles, CA); Wang, Hanguo (North Hills, CA)

    2011-12-20

    An electron tube of the present invention includes: a vacuum vessel including a face plate portion made of synthetic silica and having a surface on which a photoelectric surface is provided, a stem portion arranged facing the photoelectric surface and made of synthetic silica, and a side tube portion having one end connected to the face plate portion and the other end connected to the stem portion and made of synthetic silica; a projection portion arranged in the vacuum vessel, extending from the stem portion toward the photoelectric surface, and made of synthetic silica; and an electron detector arranged on the projection portion, for detecting electrons from the photoelectric surface, and made of silicon.

  20. Neutron tubes

    Science.gov (United States)

    Leung, Ka-Ngo; Lou, Tak Pui; Reijonen, Jani

    2008-03-11

    A neutron tube or generator is based on a RF driven plasma ion source having a quartz or other chamber surrounded by an external RF antenna. A deuterium or mixed deuterium/tritium (or even just a tritium) plasma is generated in the chamber and D or D/T (or T) ions are extracted from the plasma. A neutron generating target is positioned so that the ion beam is incident thereon and loads the target. Incident ions cause D-D or D-T (or T-T) reactions which generate neutrons. Various embodiments differ primarily in size of the chamber and position and shape of the neutron generating target. Some neutron generators are small enough for implantation in the body. The target may be at the end of a catheter-like drift tube. The target may have a tapered or conical surface to increase target surface area.

  1. Straightening tubes

    International Nuclear Information System (INIS)

    Hexagonal wrapper tubes, especially for nuclear reactor core sub-assemblies, may suffer from unacceptable bow as a result of welding wear pads to the wrapper and heat treatment. Straightening of the bow is effected by a method wherein at each of a series of axially spaced locations the faces or vertices of the tube are measured relative to a reference to determine the direction of bow at the locations. From these measurements, the appropriate axial locations for the application of corrective loading can be determined, whereby by application of the loading at a selected face or vertex for such measurements the bow is reduced. Such loading, by an actuator, can be repeated at the locations until the bow is reduced to within tolerances. (author)

  2. 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 COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PERIODIC TESTS AND 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...

  3. Boiler referruling on the Hartlepool and Heysham 1 advanced gas-cooled reactors

    International Nuclear Information System (INIS)

    The Hartlepool and Heysham I reactors each use eight cylindrical boilers having nineteen rows of helical tubes. The advantages of this design are partially offset by the relatively poor radial gas mixing. Some rows of tubing may have an imbalance between heat input from the gas and the flow of feedwater. causing a temperature profile at the upper transition joints. The thermal/hydraulic behaviour meant that the metallurgical constraints limited output. Analysis of the behaviour of these boilers required a new two-dimensional mathematical model, known as PODMIX. This describes the thermal hydraulics in each of the rows of tubing and also in the gas between the rows. Not all of the parameters for the model can be determined from first principles. However, two out of the thirty two pods have thermocouples at some of the upper transition joints and these made back calculation possible. In order to translate this model to other boiler pods, a novel thermocouple rake system was designed for sampling superheated steam temperatures in selected tubes. A result of this analysis was to show that different, individual ferrule patterns were needed for each pod. The characteristics could, in general, best be met using twin orifice ferrules. Unfortunately, the installed system did not permit the replacement of orifices, so that a completely new system had to be developed. In the course of designing this, the opportunity was taken to over come susceptibilities to erosion/corrosion and crevice corrosion. Removal of the old ferrules and replacement with the new ones necessitated the development of high precision, programmable machines to operate under difficult site conditions. These carried out drilling, boring, grinding and polishing operations as well as making face welds and tube bore welds. Modifications have already achieved substantial improvements in performance and output, but an extended, iterative programme still lies ahead. (author)

  4. Electrical design requirements for electrode boilers for nuclear plants

    International Nuclear Information System (INIS)

    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

  5. Grain boundary engineering technology : materials to reduce recovery boiler maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Rivers, K.C.; MacKenzie, C.M. [Babcock and Wilcox Canada Ltd., Cambridge, ON (Canada)

    2001-05-01

    This paper presented a new technology designed to improve the mechanical reliability of recovery boilers. Thermal fatigue and environmentally-assisted stress corrosion cracking often cause cracking in 304L composite tubes in the lower recovery furnace. In March 1999, Babcock and Wilcox Canada created Integran Technologies Inc. with co-shareholders Ontario Power Generation and Nanometals to develop and market advanced materials applications using patented Grain Boundary Engineering (GBE) and nanocrystalline technologies. The main objective was to provide their customers with a better return on equipment investments. GBE is the method by which the local grain boundary structure is characterized and the material processing variables are adjusted to create an optimized grain boundary structure that improves the performance of the material beyond that which would result from conventional processing techniques. The technology has resulted in significant improvements in intergranular corrosion cracking resistance, creep resistance and fatigue resistance. 9 refs., 4 figs.

  6. Initial study of a method for IR measurements in boilers; Inledande studie av metod foer IR-maetning i aangpannor

    Energy Technology Data Exchange (ETDEWEB)

    Sandberg, Martin; Joensson, Magnus; Lundin, Leif [Swedish National Testing and Research Inst., Boraas (Sweden)

    1999-10-01

    The tubes in steam boilers are required to be regularly inspected, in order to find water-side deposits, thinning of walls or material defects. This is for safety, problem-free operation and high availability. No non-destructive method of inspection is available today for finding deposits on the insides of boiler tubes. Nor is there any method that can not only detect deposits on the insides of the tubes but also monitor the tubes' wall thicknesses. A suitable method - reliable, safe, easy to use and cost-efficient - is therefore needed. One such method is to measure the surface temperature of a larger area of the diaphragm wall, using a non-contact method, and from the resulting information to assess the material thickness and possible water-side or steam-side deposits. An IR camera is used for non-contact measurement of the radiated energy from several adjacent surface elements, and thus also of their temperature. The temperature is displayed on the camera's screen to produce a picture of the temperature distribution. This is a well-established method today, and is used in applications such as the steel industry, the electricity industry, electronics and health care. The surface temperatures of the tube walls can be measured by inserting an IR camera on an arm into the combustion chamber, without anyone having to get inside the boiler. The combustion chamber is the part of the boiler that is of main interest for inspection, as it is the easiest to reach. Measurements are facilitated by higher temperatures and thus higher heat fluxes through the tube walls. Diaphragm wall temperatures can be measured quickly and rationally over large areas. Points of interest in inspections include determining where there are water-side deposits in the tubes, where tubes are thin, where flow is obstructed and where there might be material defects. With the exception of material defects, all of these mechanisms result in changes in the surface temperature, which in many

  7. Chemical cleaning of UK AGR boilers

    International Nuclear Information System (INIS)

    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)

  8. Boiler efficiency methodology for solar heat applications

    Science.gov (United States)

    Maples, D.; Conwell, J. C.; Pacheco, J. E.

    1992-08-01

    This report contains a summary of boiler efficiency measurements which can be applied to evaluate the performance of steam-generating boilers via both the direct and indirect methods. This methodology was written to assist industries in calculating the boiler efficiency for determining the applicability and value of thermal industrial heat, as part of the efforts of the Solar Thermal Design Assistance Center (STDAC) funded by Sandia National Laboratories. Tables of combustion efficiencies are enclosed as functions of stack temperatures and the amount of carbon dioxide and carbon monoxide in the gas stream.

  9. Superheater Corrosion In Biomass Boilers: Today's Science and Technology

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, William (Sandy) [SharpConsultant

    2011-12-01

    This report broadens a previous review of published literature on corrosion of recovery boiler superheater tube materials to consider the performance of candidate materials at temperatures near the deposit melting temperature in advanced boilers firing coal, wood-based fuels, and waste materials as well as in gas turbine environments. Discussions of corrosion mechanisms focus on the reactions in fly ash deposits and combustion gases that can give corrosive materials access to the surface of a superheater tube. Setting the steam temperature of a biomass boiler is a compromise between wasting fuel energy, risking pluggage that will shut the unit down, and creating conditions that will cause rapid corrosion on the superheater tubes and replacement expenses. The most important corrosive species in biomass superheater corrosion are chlorine compounds and the most corrosion resistant alloys are typically FeCrNi alloys containing 20-28% Cr. Although most of these materials contain many other additional additions, there is no coherent theory of the alloying required to resist the combination of high temperature salt deposits and flue gases that are found in biomass boiler superheaters that may cause degradation of superheater tubes. After depletion of chromium by chromate formation or chromic acid volatilization exceeds a critical amount, the protective scale gives way to a thick layer of Fe{sub 2}O{sub 3} over an unprotective (FeCrNi){sub 3}O{sub 4} spinel. This oxide is not protective and can be penetrated by chlorine species that cause further acceleration of the corrosion rate by a mechanism called active oxidation. Active oxidation, cited as the cause of most biomass superheater corrosion under chloride ash deposits, does not occur in the absence of these alkali salts when the chloride is present as HCl gas. Although a deposit is more corrosive at temperatures where it is molten than at temperatures where it is frozen, increasing superheater tube temperatures through

  10. photomultiplier tubes

    CERN Multimedia

    photomultiplier tubes. A device to convert light into an electric signal (the name is often abbreviated to PM). Photomultipliers are used in all detectors based on scintillating material (i.e. based on large numbers of fibres which produce scintillation light at the passage of a charged particle). A photomultiplier consists of 3 main parts: firstly, a photocathode where photons are converted into electrons by the photoelectric effect; secondly, a multiplier chain consisting of a serie of dynodes which multiply the number of electron; finally, an anode, which collects the resulting current.

  11. photomultiplier tube

    CERN Multimedia

    photomultiplier tubes. A device to convert light into an electric signal (the name is often abbreviated to PM). Photomultipliers are used in all detectors based on scintillating material (i.e. based on large numbers of fibres which produce scintillation light at the passage of a charged particle). A photomultiplier consists of 3 main parts: firstly, a photocathode where photons are converted into electrons by the photoelectric effect; secondly, a multiplier chain consisting of a serie of dynodes which multiply the number of electron; finally, an anode, which collects the resulting current.

  12. Heat Transfer Studies in Tube Banks with Integral Wake Splitters

    Directory of Open Access Journals (Sweden)

    Suzairin Md Seri

    2009-09-01

    Full Text Available This paper reports the findings from heat transfer studies with the presence of extended surfaces from tube banks which are termed as integral wake splitter plates. Employing this type of fins, investigations on heat transfer characteristics on a single circular tube as well as tube banks were carried out in cross flow of air in a rectangular duct. Experiments were carried out in the Reynolds number range 5 x 103 to 105 on a single cylinder of various splitter length-to-tube diameter ratios, L/D = 0.5, 1.0, 1.5 and 2.0. Further, tube banks consisting of 12 rows and 3 tubes per row in equilateral triangle arrangements with transverse pitch to diameter ratio, a = 2, were also investigated, the banks being made up of plain tubes or tubes with splitters. Heat transfer characteristics were studied for tubes with L/D = 0, 0.5 and 1.0 under constant heat flux conditions. Tube banks with L/D = 1.0 yielded the highest heat transfer rates. Findings from this work may be adopted to be utilized in various industrial applications such as economizer of a steam boiler, air-conditioning coils or waste heat recovery systems.

  13. Temperature Distribution of Biodiesel Blends Combustion in Boiler using CFD-Fluent

    Directory of Open Access Journals (Sweden)

    Lia Cundari

    2016-02-01

    Full Text Available The use of biodiesel have been tested on some combustion devices extensively, including on the boiler. Biodiesel blends use in boiler is possibly affected the behaviour of combustion. It can be evaluated by analysing the exhaust gas composition and temperature. This study is conducted to show the distribution of temperature in the combustion chamber and boiler stack’s using Computational Fluid Dynamic (CFD software Fluent. Experimentally, the tests carried out on the fire tube boiler vertical type cylinder with pressure of 3 bar. Temperature measurement is performed at three points in the combustion chamber and boilers’ stack using optional thermocouple and gas analyzer IMR 1400. The biodiesel used in the tests is palm oil based with blending portion varies from 5-25%. The results show that in the higher blend of biodiesel, the temperature of combustion chamber tend to be lower but the exhaust gas temperature at the end of the chimney was likely to increase. On the other hand, the simulation using FLUENT showed the pattern of temperature distribution was relatively equal between the use of biodiesel in the blends under 25% compared to the use of diesel (B0.

  14. Alkali metal pool boiler life tests for a 25 kWe advanced Stirling conversion system

    Science.gov (United States)

    Anderson, W. G.; Rosenfeld, J. H.; Noble, J.

    The overall operating temperature and efficiency of solar-powered Stirling engines can be improved by adding an alkali metal pool boiler heat transport system to supply heat more uniformly to the heater head tubes. One issue with liquid metal pool boilers is unstable boiling. Stable boiling is obtained with an enhanced boiling surface containing nucleation sites that promote continuous boiling. Over longer time periods, it is possible that the boiling behavior of the system will change. An 800-h life test was conducted to verify that pool boiling with the chosen fluid/surface combination remains stable as the system ages. The apparatus uses NaK boiling on a - 100 + 140 stainless steel sintered porous layer, with the addition of a small amount of xenon. Pool boiling remained stable to the end of life test. The pool boiler life test included a total of 82 cold starts, to simulate startup each morning, and 60 warm restarts, to simulate cloud cover transients. The behavior of the cold and warm starts showed no significant changes during the life test. In the experiments, the fluid/surface combination provided stable, high-performance boiling at the operating temperature of 700 C. Based on these experiments, a pool boiler was designed for a full-scale 25-kWe Stirling system.

  15. Ecological boiler modernization, feasible energy solutions

    International Nuclear Information System (INIS)

    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

  16. Gas fired boilers and atmospheric pollution

    International Nuclear Information System (INIS)

    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

  17. 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. PMID:22049674

  18. Transients in a circulating fluidized bed boiler

    OpenAIRE

    Baskakov, A. P.; Munts, V. A.; Pavlyuk, E. Yu.

    2013-01-01

    Transients in a circulating fluidized bed boiler firing biomass are considered. An attempt is made to describe transients with the use of concepts applied in the automatic control theory. The parameters calculated from an analysis of unsteady heat balance equations are compared with the experimental data obtained in the 12-MW boiler of the Chalmers University of Technology. It is demonstrated that these equations describe the transient modes of operation with good accuracy. Dependences for ca...

  19. The Characterization of Twin-Wire Arc-Sprayed FeCrBSi Coating and the Application in Sewage Sludge Boilers

    Science.gov (United States)

    Qin, Enwei; Huang, Qian; Shao, Yumin; Chen, Guoxing; Ye, Lin; Gu, Qin; Wu, Shuhui

    2014-12-01

    Incineration in boilers is an environment-friendly treatment for industrial and civil sewage sludge. However, due to the aggressive nature of the sludge, the boiler fireside-surface is subjected to severe wear, erosive, and high temperature corrosion problems during incineration. In this study, we developed an economical FeCrBSi wire material with iron weight content as high as 80%. The coating was prepared by twin-wire arc spraying processing. The chemical compositions of the coating, as well as phase components were analyzed by energy-dispersive spectroscopy and x-ray diffraction method. The surface roughness, porosity, and cross-sectional morphology were further characterized. The coating hardness is close to that of the commercial Armacor M and Armacor C materials. In-boiler test was also carried out. The low thickness loss of the tube indicates a promising application future in sludge boilers.

  20. Study of slagging in and blowout of P-59 boiler furnace screens during the burning of Moscow-area coal

    Energy Technology Data Exchange (ETDEWEB)

    Guzenko, S.I.; Vasil' ev, V.V.; Serebryanikov, N.I.; Panchenko, V.F.; Meelak, Kh.O.; Khaikin, I.B.; Perevezentsev, V.P.

    1978-03-01

    The operation of the burners of the P-59 boilers at the Ryazan GRES, burning Moscow area brown coal, is characterized by intense slagging of the LRP screens, especially in the zone of maximum heat formation, causing a particularly severe screen cleaning problem. The thermal efficiency of screen cleaning by steam blowout using OM-0.35 devices is low even with intense use (every 2 hours), which is accompanied by dangerous steam-ash erosion of the tubes. Water blowout of the LRP (lower radiative part) of the P-59 boiler with four long-range M-3A devices is rather effective. Under conditions of intense formation of deposits on the screens of the lower radiative part of P-59 boilers they cannot be brought up to an operationally clean state using known cleaning methods.

  1. 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. PMID:22316759

  2. The effect of water quality on reliability of boiler plants performance

    Directory of Open Access Journals (Sweden)

    Gajić Anto S.

    2010-01-01

    Full Text Available This paper presents sources and types of corrosion processes of boiler tube system of the Thermal Power Plant "Ugljevik". The main goal in the electric power production is to achieve lower prices, which can only be done by providing low maintenance costs. While it is not possible to completely stop corrosion, it could be slowed down and it's effects could be reduced. In order to reduce corrosion to a minimum on thermal power plants' vital equipment, particularly boilers, it is necessary to determine in each particular case the acting mechanism of corrosion and agents that cause it. Damages and failures on thermal power plants are largely caused by the development of various types of corrosion processes. Special attention is given to the preparation of water, considering its importance to the occurrence of corrosion. The following types of corrosion were detected on the screen tube boiler by visual examination on the side of water and steam: erosive, pitting and impact corrosion. The inner surface of screen pipes, from which the scale layer was removed, indicates that the erosive corrosion with the thinning of pipe walls occurs. Perforation of the welded screen pipes shows that stress corrosion occurred on the screen pipe with formation of cracks and that pipe exploded. Pits on the inner surface of the screen pipes, visible after the removal of scale and corrosion products, are proof that pitting corrosion occurred. The causes of corrosion were discovered and proposed measures for their elimination were given.

  3. Sodium reflux pool-boiler solar receiver on-sun test results

    Energy Technology Data Exchange (ETDEWEB)

    Andraka, C E; Moreno, J B; Diver, R B; Moss, T A [Oak Ridge National Lab., TN (United States)

    1992-06-01

    The efficient operation of a Stirling engine requires the application of a high heat flux to the relatively small area occupied by the heater head tubes. Previous attempts to couple solar energy to Stirling engines generally involved directly illuminating the heater head tubes with concentrated sunlight. In this study, operation of a 75-kW{sub t} sodium reflux pool-boiler solar receiver has been demonstrated and its performance characterized on Sandia's nominal 75-kW{sub t} parabolic-dish concentrator, using a cold-water gas-gap calorimeter to simulate Stirling engine operation. The pool boiler (and more generally liquid-metal reflux receivers) supplies heat to the engine in the form of latent heat released from condensation of the metal vapor on the heater head tubes. The advantages of the pool boiler include uniform tube temperature, leading to longer life and higher temperature available to the engine, and decoupling of the design of the solar absorber from the engine heater head. The two-phase system allows high input thermal flux, reducing the receiver size and losses, therefore improving system efficiency. The receiver thermal efficiency was about 90% when operated at full power and 800{degree}C. Stable sodium boiling was promoted by the addition of 35 equally spaced artificial cavities in the wetted absorber surface. High incipient boiling superheats following cloud transients were suppressed passively by the addition of small amounts of xenon gas to the receiver volume. Stable boiling without excessive incipient boiling superheats was observed under all operating conditions. The receiver developed a leak during performance evaluation, terminating the testing after accumulating about 50 hours on sun. The receiver design is reported here along with test results including transient operations, steady-state performance evaluation, operation at various temperatures, infrared thermography, x-ray studies of the boiling behavior, and a postmortem analysis.

  4. Sodium reflux pool-boiler solar receiver on-sun test results

    Science.gov (United States)

    Andraka, C. E.; Moreno, J. B.; Diver, R. B.; Moss, T. A.

    1992-06-01

    The efficient operation of a Stirling engine requires the application of a high heat flux to the relatively small area occupied by the heater head tubes. Previous attempts to couple solar energy to Stirling engines generally involved directly illuminating the heater head tubes with concentrated sunlight. In this study, operation of a 75-kW(sub t) sodium reflux pool-boiler solar receiver has been demonstrated and its performance characterized on Sandia's nominal 75-kW(sub t) parabolic-dish concentrator, using a cold-water gas-gap calorimeter to simulate Stirling engine operation. The pool boiler (and more generally liquid-metal reflux receivers) supplies heat to the engine in the form of latent heat released from condensation of the metal vapor on the heater head tubes. The advantages of the pool boiler include uniform tube temperature, leading to longer life and higher temperature available to the engine, and decoupling of the design of the solar absorber from the engine heater head. The two-phase system allows high input thermal flux, reducing the receiver size and losses, therefore improving system efficiency. The receiver thermal efficiency was about 90 percent when operated at full power and 800 C. Stable sodium boiling was promoted by the addition of 35 equally spaced artificial cavities in the wetted absorber surface. High incipient boiling superheats following cloud transients were suppressed passively by the addition of small amounts of xenon gas to the receiver volume. Stable boiling without excessive incipient boiling superheats was observed under all operating conditions. The receiver developed a leak during performance evaluation, terminating the testing after accumulating about 50 hours on sun. The receiver design is reported here along with test results including transient operations, steady-state performance evaluation, operation at various temperatures, infrared thermography, x-ray studies of the boiling behavior, and a postmortem analysis.

  5. Experience gained from shifting a PK-19 boiler to operate with increased superheating and with a load higher than its rated value

    Science.gov (United States)

    Kholshchev, V. V.

    2011-08-01

    Failures of steam superheater tubes occurred after the boiler was shifted to operate with a steam temperature of 540°C. The operation of the steam superheater became more reliable after it had been subjected to retrofitting. The modernization scheme is described. An estimate is given to the temperature operating conditions of tubes taking into account the thermal-hydraulic nonuniformity of their heating.

  6. Improvement in super heater deposition of straw boiler based on numerical simulation

    Energy Technology Data Exchange (ETDEWEB)

    Tai, Lv; Zhou, Ting-ting; Wang, Hai [Northeast Dianli Univ., Jilin (China). College of Energy and Power Engineering

    2013-07-01

    There is the problem of deposition exits generally in straw boiler super heater due to chlorine and alkalescent substance consists in the straw fuel, which agglomerate combustion material, especially for crops. Deposition does not only behave to raise the tube temperature, but also accelerate corrosion, even hide cartridge igniter trouble. This paper based on the study of some 75 t/h plant to optimize the ash removal system of super heater. According to the CFD simulation, the flue flow situation in tube bundle of super heater diverse along with the position of the tube. Based on the regular of deposit researched from the simulation outcome, this paper propose to optimize the structure of shock wave soot blower of pattern BH-100 used by the plant, which did not performance a proper role.

  7. Research and design of 330 MW circulating fluidized bed boiler

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xianbin; Shi, Zhenghai; Huang, Zhong [Thermal Power Research Institute, Xi' an (China); Jiang, Minhua [China Huaneg Group, Beijing (China); Yu, Long; Zhang, Yanjun; Wang, Fengjun; Zhang, Man [Harbin Boiler CO., Ltd, Harbin (China)

    2013-07-01

    Based on research and manufacture of 210MW circulating fluidized bed (CFB) boiler, the key technologies of large CFB boiler have been Research, the plan design of 330MW CFB boiler have been performed, construction design of key components and scaling up characteristics were analysed, The 330MW CFB boiler designed demonstration project has been put into commercial operation, It is the largest capacity CFB boiler operated in china now, Operation of 330MW CFB boiler was stable and good performance has been proved.

  8. Fuel sulfur and boiler fouling

    Energy Technology Data Exchange (ETDEWEB)

    Litzke, W.; Celebi, Y.; Butcher, T. [Brookhaven National Lab., Upton, NY (United States)

    1995-04-01

    Fouling of the heat transfer surfaces of boilers and furnaces by `soot` leads to reduced efficiency and increased service requirements. The average level of annual efficiency reduction as a result of fouling if generally accepted as 2% per year. Improving the efficiency of equipment in the field may be the most important oil heat conservation opportunity at present. Improvements can be realized by reducing fouling rates, promoting lower firing rates in existing equipment, and enabling excess air levels to be set lower without raising concerns about increased service requirements. In spite of the importance of efficiency in the field there is very little data available on efficiency degradation rates with modern equipment, actual field operating conditions (excess air and smoke number settings) and service problems which affect efficiency. During 1993-94 field tests were initiated to obtain such data and to obtain information that would compliment existing and current laboratory work. Experimental work conducted on a bench scale level have included tests with various advanced burners, fuel types, and different operating conditions which have been done at the BNL Rapid Fouling Test Facility. This report will focus on the field study of fouling effects on ten residential heating service problems at each site are summarized. In addition, the technical difficulties involved with conducting such a field study shall also be discussed as the findings should serve to improve future work in this area.

  9. Characterization of model boiler specimens

    International Nuclear Information System (INIS)

    This paper describes the general results of an investigation of three crevice corrosion samples provided by Westinghouse from the S112-1 Model Boiler Program. These samples had all been formed under essentially the same initial chemical conditions, but two had been treated with inhibitors at the end of the experimental runs. The first received no neutralization during the model runs, the second was treated with Ca(OH)2 and the third was treated with boric acid. The samples were prepared for examination in several different ways. The samples were characteristic of dented intersections and had the general conformation of a thin-walled inner Inconel cylinder within a thick-walled carbon steel cylinder. An original 12-mil inter-cylinder gap had been packed with powdered magnetite. This magnetite had been augmented by further growth of magnetite during the model runs, making the oxide layer considerably thicker than the original 12-mils in some areas of the samples. The cylinders were sectioned and polished perpendicular to their long axes and the resulting surfaces examined

  10. 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.

  11. Catalytic and chemical properties of boiler deposits from Orimulsion{sup TM} fuel

    Energy Technology Data Exchange (ETDEWEB)

    Rasmussen, S.B. [Technical Univ. of Denmark (Denmark). Dept. of Chemistry; Hagen, S.U.; Masters, S.G.; Hagen, A.; Staahl, K.; Eriksen, K.M.; Simonsen, P.; Jensen, J.N.; Berg, M.; Fehrmann, R.; Chorkendorff, I.

    2003-06-01

    Bulk and surface analyses have been conducted for selected deposit samples from an Orimulsion{sup TM} fired boiler unit at the Asnaes power plant in Kalundborg, Denmark. Analyses of the composition show that the deposits on the boiler tubes contain significant quantities of vanadium, calcium, nickel and sulfur. Furthermore the SO{sub 2} oxidation activity of the collected samples has been measured as a function of oxygen and SO{sub 2} content in the flue gas and of the gas temperature. The results show a significant SO{sub 2} oxidation capability in the temperature range 530-670 C. The catalytic oxidation reaction on the deposits is found to be a gas-solid, heterogeneously catalyzed reaction. The catalytically active species have been determined as surface oxo vanadium compounds with vanadium in a formal oxidation state between +IV and +V. (orig.)

  12. ENVIRONMENTAL ASPECTS OF MODERNIZATION OF HIGH POWER WATER-HEATING BOILERS

    Directory of Open Access Journals (Sweden)

    P. M. Glamazdin

    2016-01-01

    Full Text Available Boilers of KVGM and PTVM series are characterized by high values of NOx and CO content in the combustion products. Reduction of NOx and CO content can be achieved by two ways: by installing the condensing heat recovery unit at the boiler outlet and by improving the heat and mass transfer processes in boiler furnaces. Application of the condensing heat recovery units causes pollution of resulting condensate by low-concentration acids. The authors conducted a study in order to determine the effectiveness of the previously applied methods of suppressing the emission of nitrogen oxides in the boilers of these types. Equalization of the temperature field and, consequently, enhancement of heat transfer in the furnace by substitution the used burners by the more advanced ones, the design of which facilitates reduction the emission of nitrogen oxides, were applied to all the upgraded facilities. The studies fulfilled demonstrate that a reduction of NOx emissions in water-heating high power boilers is fairly possible by means of modernization of the latter. The authors have developed the project of the PTVM-30 boiler modernization, which was implemented at a large boiler plant in the city of Vinnitsa (Ukraine. The project included a number of technical solutions. Six burners were replaced by the two ones that were located in the hearth; also the hearth screen was dismantled. At the same time, reducing the total surface area of the heating caused by the exclusion of hearth screen was compensated by filling the locations of the six embrasures of staff burners on the side screens with straightened furnace tubes. Installing the burners separate from the screen made it possible to eliminate the transfer of vibration to the furnace tubes, and – via them – to the boilers setting. Automation provided “associated regulations”. Draught machines were equipped with frequency regulators. During commissioning of the boiler the studies were carried out that

  13. Hot Corrosion at Air-Ports in Kraft Recovery Boilers

    Energy Technology Data Exchange (ETDEWEB)

    Holcomb, Gordon R.; Covino, Bernard S., Jr.; Russell, James H.

    2003-01-01

    Hot corrosion can occur on the cold-side of airports in Kraft recovery boilers. The primary corrosion mechanism involves the migration of sodium hydroxide and potassium hydroxide vapors through leaks in the furnace wall at the airports and their subsequent condensation. It has been reported that stainless steel is attacked much faster than carbon steel in composite tubes, and that carbon steel tubing, when used with a low-chromium refractory, does not exhibit this type of corrosion. For hot corrosion fluxing of metal oxides, either acidic or basic fluxing takes place, with a solubility minimum at the basicity of transition between the two reactions. For stainless steel, if the basicity of the fused salt is between the iron and chromium oxide solubility minima, then a synergistic effect can occur that leads to rapid corrosion. The products of one reaction are the reactants of the other, which eliminates the need for rate-controlling diffusion. This effect can explain why stainless steel is attacked more readily than carbon steel.

  14. Performance evaluation of a biomass boiler on the basis of heat loss method and total heat values of steam

    International Nuclear Information System (INIS)

    Pakistan being an agricultural country has large resources of biomass in the form of crop residues like wood, wheat straw, rice husk, cotton sticks and bagasse. Power generation using biomass offers an excellent opportunity to overcome current scenario of energy crises. Of the all biomass resources, bagasse is one of the potential energy sources which can be successfully utilized for power generation. During the last decade, bagasse fired boilers attained major importance due to increasing prices of primary energy (e.g. fossil fuels). Performance of a bagasse fired boiler was evaluated at Shakarganj Sugar Mill, Bhone-Jhang having steam generation capacity of 80 tons h/sup -1/at 25 bar working pressure. The unit was forced circulation and bi-drum type water tube boiler which was equipped with all accessories like air heater, economizer and super-heater. Flue gas analyzer and thermocouples were used to record percent composition and temperature of flue gases respectively. Physical analysis of bagasse showed gross calorific value of bagasse as 2326 kCal kg/sup -1/. Ultimate analysis of bagasse was performed and the actual air supplied to the boiler was calculated to be 4.05 kg per kg of bagasse under the available resources of the plant. Performance evaluation of the boiler was carried out and a complete heat balance sheet was prepared to investigate the different sources of heat losses. The efficiency of the boiler was evaluated on the basis of heat losses through boiler and was found to be 56.08%. It was also determined that 2 kg of steam produced from 1 kg of bagasse under existing condition of the boiler. The performance evaluation of the boiler was also done on the basis of total heat values of steam and found to be 55.98%. The results obtained from both the methods were found almost similar. Effects of excess air, stack and ambient temperature on the efficiency of boiler have also been evaluated and presented in the manuscript. (author)

  15. Identification and optimization studies of the dynamics of a small experimental boiler

    International Nuclear Information System (INIS)

    A small experimental boiler has been constructed and identification and optimization studies of the dynamic characteristics of the boiler made. The boiler consists of an electrical heater which heats single phase water passing through the centre of the heater tubes. The water is contained in a continuous loop and is pumped around the circuit. The added enthalpy which the water receives from the heater is transported via a pipe to a heat exchanger. The primary side of this heat exchanger is formed by part of the pipe which forms the continuous loop and the secondary side of the heat exchanger consists of a simple boiler. The pump to provide the necessary circulation is positioned between the heat exchanger outlet and the heater inlet. Facilities exist for modulating the heat supplied by the heater and the flow in the continuous loop which couples the heater to the boiler (here and elsewhere in this report the word heat is used to denote heat flow). Steady state and transient measurements have been made and a mathematical model of the dynamics of this system developed and compared against experimentally determined dynamic responses. The latter are derived by perturbing the heat input and continuous loop mass flow with a suitable pseudo-random binary chain code and by then calculating on line the cross-correlation functions between responses - temperatures, water level and mass flows and the perturbing signals. Equivalent impulse responses are determined in a digital simulation of the mathematical model. The model is then adjusted to give agreement with the experimental responses. This adjustment is performed by an optimization scheme based on the minimum mean square deviation of the two sets of system transient responses. (author)

  16. Design of a pool boiler heat transport system for a 25 kWe advanced Stirling conversion system

    Science.gov (United States)

    Anderson, W. G.; Rosenfeld, J. H.; Noble, J.; Kesseli, J.

    The overall operating temperature and efficiency of solar-powered Stirling engines can be improved by adding a heat transport system to more uniformly supply heat to the heater head tubes. One heat transport system with favorable characteristics is an alkali metal pool boiler. An alkali metal pool boiler heat transport system was designed for a 25-kW advanced Stirling conversion system (ASCS). Solar energy concentrated on the absorber dome boils a eutectic mixture of sodium and potassium. The alkali metal vapors condense on the heater head tubes, supplying the Stirling engine with a uniform heat flux at a constant temperature. Boiling stability is achieved with the use of an enhanced boiling surface and noncondensible gas.

  17. Degradation of superheater tubes made of austenitic T321H steel after long term service

    Energy Technology Data Exchange (ETDEWEB)

    Hernas, Adam [Silesian Technical Univ., Katowice (Poland). Faculty of Material Science; Augustyniak, Boleslaw; Chmielewski, Marek [Gdansk Univ. of Technology (Poland). Mechanical Dept.; Sablik, M.J. [Applied Magnetic and Physical Modeling, LLC, San Antonio, TX (United States)

    2010-07-01

    There are presented results of complementary tests performed for the evaluation of creep damage in austenitic steel grade T321H exploited over 200,000 hours in the secondary superheater part of a power plant boiler. The following techniques have been applied: SEM microscopy, X-ray diffraction, tensile tests, hardness measurements and novel eddy current inspection. The novel eddy current inspection is proposed as a non-destructive method of estimating the creep damage stage of austenite steel boiler tubes after long-term service in power plants. We compare the results provided by the different techniques and discuss the correlations and also point out the problems which need to be addressed in order to elaborate the remaining life assessment of austenitic boiler tubes. (orig.)

  18. Soft Sensor for Oxide Scales on the Steam Side of Superheater Tubes under Uneven Circumferential Load

    OpenAIRE

    Qing Wei Li; Gui Huan Yao

    2015-01-01

    A soft sensor for oxide scales on the steam side of superheater tubes of utility boiler under uneven circumferential loading is proposed for the first time. First finite volume method is employed to simulate oxide scales growth temperature on the steam side of superheater tube. Then appropriate time and spatial intervals are selected to calculate oxide scales thickness along the circumferential direction. On the basis of the oxide scale thickness, the stress of oxide scales is calculated by t...

  19. Super-heater tube failure due to overheating when using bagasse as fuel

    OpenAIRE

    John Jairo Coronado Marín

    2010-01-01

    A super-heater’s boiler tubes presented external longitudinal cracks. The tubes’ external surfaces presented a reddish-white layer consisting of paraffin chains: CH, functional groups: CO, NH and sulphur compounds. This brittle layer prevented heat transfer, thereby causing increased tube temperature. Creep led to failure due to long-term overheating. The steel tubes’ microstructure presented grain growth, cementite globulisation and intergranular cracks on the external surface. The foregoing...

  20. Failure analysis of high temperature superheater tube (HTS) of a pulverized coal-fired power station

    OpenAIRE

    Md. Mujibur Rahman; Ahmad Kamal Kadir

    2011-01-01

    This paper presents the failure investigation of high temperature superheater (HTS) tubes.  Samples were collected from one of the coal fired power plants in Malaysia, namely, Stesen Janakuasa Sultan Azlan Shah, Manjung (Manjung Power Station).  After eight years of non-continuous services of three boilers, welded support-clips were completely separated (detached) from (HTS) tubes, which caused the wall thinning.  Collected failed samples were undergone several experimental investigations inc...

  1. Premature failure of dissimilar metal weld joint at intermediate temperature superheater tube

    OpenAIRE

    Mohammed Al Hajri; Anees U. Malik; Abdelkader Meroufel; Fahd Al-Muaili

    2015-01-01

    Dissimilar metal weld (DMW) joint between alloyed steel (AS) and stainless steel (SS) failed at one of intermediate temperature superheater (ITSH) tube in steam/power generation plant boiler. The premature failure was detected after a relatively short time of operation (8 years) where the crack propagated circumferentially from AS side through the ITSH tube. Apart from physical examination, microstructural studies based on optical microscopy, SEM and EDX analysis were performed. The results o...

  2. 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.

  3. Boiler MACT Technical Assistance (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2012-03-01

    Fact sheet describing the changes to Environmental Protection Act process standards. The DOE will offer technical assistance to ensure that major sources burning coal and oil have information on cost-effective, clean energy strategies for compliance, and to promote cleaner, more efficient boiler burning to cut harmful pollution and reduce operational costs. The U.S. Environmental Protection Agency (EPA) is expected to finalize the reconsideration process for its Clean Air Act pollution standards National Emissions Standards for Hazardous Air Pollutants for Major Sources: Industrial, Commercial, and Institutional Boilers and Process Heaters (known as Boiler Maximum Achievable Control Technology (MACT)), in Spring 2012. This rule applies to large and small boilers in a wide range of industrial facilities and institutions. The U.S. Department of Energy (DOE) will offer technical assistance to ensure that major sources burning coal or oil have information on cost-effective clean energy strategies for compliance, including combined heat and power, and to promote cleaner, more efficient boilers to cut harmful pollution and reduce operational costs.

  4. Tracheostomy tube - eating

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000464.htm Tracheostomy tube - eating To use the sharing features on ... when you swallow foods or liquids. Eating and Tracheostomy Tubes When you get your tracheostomy tube, or ...

  5. Establishment of Optimum Ecological System for Monitoring Boiler Units

    OpenAIRE

    V. I. Nazarov

    2014-01-01

    A mathematical model has been proposed for ecological monitoring of a boiler unit. This model makes it possible to obtain maximum decrease in effluents at minimum reduction in economical operational efficiency of the boiler unit.

  6. Titanium condenser tubes

    International Nuclear Information System (INIS)

    The corrosion resistance of titanium in sea water is extremely excellent, but titanium tubes are expensive, and the copper alloy tubes resistant in polluted sea water were developed, therefore they were not used practically. In 1970, ammonia attack was found on the copper alloy tubes in the air-cooled portion of condensers, and titanium tubes have been used as the countermeasure. As the result of the use, the galvanic attack an copper alloy tube plates with titanium tubes as cathode and the hydrogen absorption at titanium tube ends owing to excess electrolytic protection were observed, but the corrosion resistance of titanium tubes was perfect. These problems can be controlled by the application of proper electrolytic protection. The condensers with all titanium tubes adopted recently in USA are intended to realize perfectly no-leak condensers as the countermeasure to the corrosion in steam generators of PWR plants. Regarding large condensers of nowadays, three problems are pointed out, namely the vibration of condenser tubes, the method of joining tubes and tube plates, and the tubes of no coolant leak. These three problems in case of titanium tubes were studied, and the problem of the fouling of tubes was also examined. The intervals of supporting plates for titanium tubes should be narrowed. The joining of titanium tubes and titanium tube plates by welding is feasible and promising. The cleaning with sponge balls is effective to control fouling. (Kako, I.)

  7. A portable gamma backscatter gauge for measurement of wall thickness of pipes and boilers

    International Nuclear Information System (INIS)

    A portable instrument for 'in situ' measurement of wall thickness of boilers and tubes, working on the principle of gamma back-scattering, and using a low activity gamma source (30 micro-curies Co60) and a scintillation detector is described. The probe consists of a gamma source and an NaI(tl) scintillation detector coupled to a multiplier phototube. The EHT circuit for the PM tube and the preamplifier are also incorporated inside the probe. The probe is coupled to a measuring part consisting of an amplifier for amplifying the pulses from the probe, a single channel analyser which is set to select pulses corresponding to energy of backscattered gammas and a count-rate meter to count the number of pulses. With prior calibration, count-rate can be correlated to the thickness of the backscatter eg. boiler wall or tube wall. The instrument can measure wall thicknesses upto 2 cm of steel with an accuracy of +- 10%. The unit can also be used for detection of erosion and blocking in pipes carrying process materials. The electronic circuitry is fully transistorised and works on readily available flashlight cells. The complete system is portable and well suited for field use. (author)

  8. 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 ...

  9. Modelling and predictive control of a drum-type boiler

    OpenAIRE

    Molloy, Barbara

    1997-01-01

    Boilers generate steam continuously and on a large scale. Controlling the boiler process is extremely difficult - it is a highly nonlinear process, its dynamics vary with load and it is strongly multivariable. It is also inherently unstable due to the integrator effect of the drum. In addition, boilers are commonly used in situations where the load can change suddenly and without prior warning. Traditionally, boilers have been controlled by Single-Input, Single-Output (SISO) Proportional ...

  10. 超超临界机组锅炉异种钢小径管镍基焊接接头超声波检测%Ultrasonic Flaw Detection of Dissimilar Steel Small-Diameter Tube Nickel-Based Welding Joint of Boiler of Ultra-Supercritical Units

    Institute of Scientific and Technical Information of China (English)

    邓宏平; 龙会国; 邹健伟; 谢亿

    2012-01-01

    针对超声检测火力发电厂锅炉小径管奥氏体钢与低合金钢对接异种钢焊缝的技术难题,文章通过理论分析、试验研究及现场检测验证,研究了常规小径管探头异种钢焊缝超声波检测方法。结果表明,对于如熔合线裂纹类缺陷选用小角度探头(K1~1.5)效果较佳;对于焊缝内缺陷宜选用大角度探头(K2~2.5)。利用该方法能有效检测出焊缝内各种缺陷,保证了机组安全运行也取得了较好的经济效益,对异种钢焊缝小径管超声波检测具有较强的借鉴意义。%In order to solve the ultrasonic testing technical problem of dissimilar steel small diameter tube nickel butt welding of austenitic steel and low alloy steel in thermal power plant, one new ultrasonic inspection method with small diameter tube adapted ultrasonic probe was researched by theory verification, experimental data and field experience. The results showed that the degrees of the influences of different defects on ultrasonic testing parameters were different. Better sensitivity for the fusion zone cracking in dissimilar steel small-diameter tube welding joint testing was obtained when K value of transverse wave probe was small, such as KI~I. 5. And it is good that K value of transverse wave probe was big {K2~2. 5) for internal defects in dissimilar steel small-diameter tube welding joint testing. This detective means had good detection effect for various excessive weld defects, which could ensure the safe operation of power units, improve economic benefits. The detection method mentioned in this paper could give assistance to the ultrasonic testing of dissimilar steel small-diameter tube welds.

  11. Experimental installation with pressurized fluidized bed boiler

    Energy Technology Data Exchange (ETDEWEB)

    Dobrzanski, W.; Szwarc, W.; Jurek, K.; Prokop, A. (Politechnika Warszawska (Poland). Instytut Techniki Cieplnej)

    1990-01-01

    Describes a test installation with a 3 MW pressurized fluidized bed boiler. The installation was commissioned at the Institute of Heat Engineering at the Technical University in Warsaw. Predesign assumptions and the lay-out of the installation are given. A schematic diagram of the pressurized (0.6 MPa) fluidized bed boiler with an inner diameter of 1.4 m and a total height of 5.45 m is shown. The fuel feeding system consists of a coal and adsorbent container, two feeders and an air jet pump for pneumatic transport. A water type boiler is integrated into the pressure vessel. Flue gas cyclones are also integrated into a separate pressure vessel. The computerized control system and instrumentation are described. Temperatures, pressures, pressure differences, rotational speeds and the chemical composition of gases are monitored.

  12. Evaluation of thermal overload in boiler operators.

    Science.gov (United States)

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

    2012-01-01

    The Brazilians educational institutions need a large energy demand for the operation of laundries, restaurants and accommodation of students. Much of that energy comes from steam generated in boilers with wood fuel. The laboral activity in boiler may present problems for the operator's health due to exposure to excessive heat, and its operation has a high degree of risk. This paper describes an analysis made the conditions of thermal environment in the operation of a B category boiler, located at a Higher Education Institution, located in the Zona da Mata Mineira The equipments used to collect data were Meter WBGT of the Heat Index; Meter of Wet Bulb Index and Globe Thermometer (WBGT); Politeste Instruments, an anemometer and an Infrared Thermometer. By the application of questionnaires, the second phase consisted of collecting data on environmental factors (temperature natural environment, globe temperature, relative humidity and air velocity). The study concluded that during the period evaluated, the activity had thermal overload. PMID:22316768

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

    OpenAIRE

    B. A. Bayrashevsky; N. P. Borushko

    2014-01-01

    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/∂ξ)Δξ 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 effici...

  14. 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...

  15. 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...

  16. 49 CFR 230.36 - Hydrostatic testing of boilers.

    Science.gov (United States)

    2010-10-01

    ... Appurtenances Pressure Testing of Boilers § 230.36 Hydrostatic testing of boilers. (a) Time of test. The... following any hydrostatic test where the pressure exceeds MAWP. ... 49 Transportation 4 2010-10-01 2010-10-01 false Hydrostatic testing of boilers. 230.36 Section...

  17. Lower price for solar boilers must improve market penetration

    International Nuclear Information System (INIS)

    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

  18. Aspects of new material application for boilers construction

    International Nuclear Information System (INIS)

    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

  19. Central heating: fossil-fired boilers

    Energy Technology Data Exchange (ETDEWEB)

    Blazek, C.F.; Baker, N.R.; Tison, R.R.

    1979-05-01

    This evaluation provides performance and cost data for fossil-fuel-fired steam boilers, hot-water generators, and thermal fluid generators currently available from manufacturers. Advanced-technology fluidized-bed boilers also are covered. Performance characteristics investigated include unit efficiencies, turndown capacity, and pollution requirements. Costs are tabulated for equipment and installation of both field-erected and packaged units. The information compiled in this evaluation will assist in the process of selecting energy-conversion units required for industrial, commercial, and residential applications.

  20. Planning Annual Shutdown Inspection for BFB Boiler

    OpenAIRE

    Sorsa, Tatu

    2014-01-01

    The goal of this thesis was to create an illustrative guidebook of annual inspection planning for BFB boiler to help power plant operator when planning of annual inspection is topical. This thesis was made for Andritz Oy and it is based on inspection reports and experiences of BFB boiler’s maintenance and inspection staff. In this thesis it is shown how to plan an annual inspection for BFB boiler and thesis gives good tools and hints for operator to manage inspection from the beginning ...

  1. The level control of the boiler drum

    OpenAIRE

    He, Chenhui

    2014-01-01

    Level control uses the boiler drum as a controlled object, and uses the level as a controller value. By making sure the level control is attached accurately we get better dynamic performance. I use the cascade control to make the difference to the traditional control. In this thesis, I summarize many problems with the level control in the steam boiler field as the false level phenomenon. I design three methods for the level control process system with different ways. I make the final choi...

  2. Transients in a circulating fluidized bed boiler

    Science.gov (United States)

    Baskakov, A. P.; Munts, V. A.; Pavlyuk, E. Yu.

    2013-11-01

    Transients in a circulating fluidized bed boiler firing biomass are considered. An attempt is made to describe transients with the use of concepts applied in the automatic control theory. The parameters calculated from an analysis of unsteady heat balance equations are compared with the experimental data obtained in the 12-MW boiler of the Chalmers University of Technology. It is demonstrated that these equations describe the transient modes of operation with good accuracy. Dependences for calculating the time constants of unsteady processes are obtained.

  3. Distributed parameter modeling and thermal analysis of a spiral water wall in a supercritical boiler

    Directory of Open Access Journals (Sweden)

    Zheng Shu

    2013-01-01

    Full Text Available In this paper, a distributed parameter model for the evaporation system of a supercritical spiral water wall boiler is developed based on a 3-D temperature field. The mathematical method is formulated for predicting the heat flux and the metal-surface temperature. The results show that the influence of the heat flux distribution is more obvious than that of the heat transfer coefficient distribution in the spiral water wall tube, and the peak of the heat transfer coefficient decreases with an increment of supercritical pressure. This distributed parameter model can be used for a 600 MW supercritical-pressure power plant.

  4. Experimental Study on Heat Transfer Characteristics of Shell and Tube Heat Exchanger Using Hitran Wire Matrix Turbulators As Tube Inserts.

    Directory of Open Access Journals (Sweden)

    Manoj

    2014-06-01

    Full Text Available Shell and tube heat exchangers are extensively used in boilers, oil coolers, pre-heaters, condensers etc. They are also having special importance in process application as well as refrigeration and air conditioning industries. The present paper emphasizes on heat transfer characteristics of shell and tube heat exchangers with the aid of hiTRAN wire matrix inserts is been studied. Investigations were made on effect of mass flow rate of water on heat transfer characteristics in case of plain tube without inserts. When hiTRAN wire matrix tube inserts are used, which effectively increases the turbulence of tube side flow due to the hydrodynamic and thermal agitation of boundary layer in turns increases additional pressure drop is available in the system. This results in increase in the wall shear, reduced wall temperature which enhances substantial increase in tube side heat transfer characteristics. Heat and cooling processes streams is a standard operation in many industries this operation is often performed in heat exchangers where the heated or cold fluid flows under laminar conditions inside the tubes the mechanisms of under those flow conditions are complex poorly understood since they can involve both forced and natural convection making accurate prediction for heat exchanger. Heat transfer in laminar flow regimes is low by default but can be greatly increased by the use of passive heat transfer enhancement such as tube inserts. The present analysis the hiTRAN wire matrix turbulators were used and increased heat transfer characteristics as expected outcomes.

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

    Directory of Open Access Journals (Sweden)

    B. A. Bayrashevsky

    2014-06-01

    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.

  6. Optimization of Bed Material Consumption in a CFBC Boiler

    Directory of Open Access Journals (Sweden)

    Ashish M. Pullekunnel

    2015-01-01

    Full Text Available The proposed Case-Study is to identify the scope of energy conservation and cost saving through optimization of bed material in a CFBC Boiler during plant start up. The study was undertaken at Abhijeet MADC Nagpur Energy Pvt. Ltd (AMNEPL, a 4X61.5 MW power plant at MIHAN, Khairy Khurd, Hingna, Nagpur. The scope of the study covers the savings achieved during light up of 4X250 TPH boiler and the effect of the application of the proposed method on the energy conservation possibilities and efficiency of boiler operation. The proposed method is an alternative to the conventional boiler light up of a CFBC boiler

  7. Dynamic Boiler Performance:Modelling, simulating and optimizing boilers for dynamic operation

    OpenAIRE

    Sørensen, Kim

    2004-01-01

    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 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 dyna...

  8. Environmental control during steam boiler washing

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, Marcio A.B.; Abreu Pereira, Vera L. de [Companhia Petroquimica do Nordeste (COPENE), Camacari, BA (Brazil). Div. de Engenharia Ambiental; Ringler, Ulrich E.S. [PROMON Engenharia Ltda., Salvador, BA (Brazil)

    1993-12-31

    The washing and chemical cleaning of boilers, activities of a high polluting potential, are responsible for the generation of wastewater of high contents of heavy metals, suspended solids and chemical oxygen demand (COD). This paper describes the actions carried out by COPENE - Petroquimica do Nordeste S/A - in order to reduce this problem. (author). 10 refs., 3 figs., 2 tabs.

  9. REBURN TECHNOLOGY FOR BOILER NOX CONTROL

    Science.gov (United States)

    The paper reports the progress principally of design-relate phases of a demonstration of reburning on a large cyclone-fired boiler, for which coal is the primary fuel and natural gas, the reburn fuel. Reburn system design criteria are presented, as well as the methodology and res...

  10. The investigation of the locomotive boiler material

    International Nuclear Information System (INIS)

    In the paper, the history of narrow-gauge railway system is described. The other information about the steam locomotive construction, as well as the technical regulations of its construction and exploitation are also done. The results of the studies of the locomotive boiler material are presented. (authors)

  11. 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. PMID:18822819

  12. Infrared imaging of fossil fuel power plant boiler interiors

    Science.gov (United States)

    Howard, James W.; Cranton, Brian W.; Armstrong, Karen L.; Hammaker, Robert G.

    1997-08-01

    Fossil fuel power plant boilers operate continuously for months at a time, typically shutting down only for routine maintenance or to address serious equipment failures. These shutdowns are very costly, and diagnostic tools and techniques which could be used to minimize shutdown duration and frequency are highly desirable. Due to the extremely hostile environment in these boilers, few tools exist to inspect and monitor operating boiler interiors. This paper presents the design of a passively cooled, infrared borescope used to inspect the interior of operating boilers. The borescope operates at 3.9 micrometer, where flame is partially transparent. The primary obstacles overcome in the instrument design were the harsh industrial environment surrounding the boilers and the high temperatures encountered inside the boilers. A portable yet durable lens system and enclosure was developed to work with a scanning radiometer to address these two problems by both shielding the radiometer from the environment and by extending the optical train into a snout designed to be inserted into access ports on the sides of the boiler. In this manner, interior images of the boiler can be made while keeping the radiometer safely outside the boiler. The lens views a 40 degree field of view through any 2.5' or larger opening in a foot thick boiler wall. Three of these borescopes have been built, and high resolution images of boiler interiors have been obtained.

  13. Characteristics and sources of intermediate size particles in recovery boilers : final project report.

    Energy Technology Data Exchange (ETDEWEB)

    Baxter, Larry L. (Brigham Young University, Provo, UT); Shaddix, Christopher R.; Verrill, Christopher L. (Georgia Institute of Technology, Institute of Paper Science and Technology, Atlanta, GA); Wessel, Richard A. (Babcock & Wilcox Company, Barberton, OH)

    2005-02-01

    As part of the U.S. Department of Energy (DOE) Office of Industrial Technologies (OIT) Industries of the Future (IOF) Forest Products research program, a collaborative investigation was conducted on the sources, characteristics, and deposition of particles intermediate in size between submicron fume and carryover in recovery boilers. Laboratory experiments on suspended-drop combustion of black liquor and on black liquor char bed combustion demonstrated that both processes generate intermediate size particles (ISP), amounting to 0.5-2% of the black liquor dry solids mass (BLS). Measurements in two U.S. recovery boilers show variable loadings of ISP in the upper furnace, typically between 0.6-3 g/Nm{sup 3}, or 0.3-1.5% of BLS. The measurements show that the ISP mass size distribution increases with size from 5-100 {micro}m, implying that a substantial amount of ISP inertially deposits on steam tubes. ISP particles are depleted in potassium, chlorine, and sulfur relative to the fuel composition. Comprehensive boiler modeling demonstrates that ISP concentrations are substantially overpredicted when using a previously developed algorithm for ISP generation. Equilibrium calculations suggest that alkali carbonate decomposition occurs at intermediate heights in the furnace and may lead to partial destruction of ISP particles formed lower in the furnace. ISP deposition is predicted to occur in the superheater sections, at temperatures greater than 750 C, when the particles are at least partially molten.

  14. Identification of thermal boundary conditions in heat exchangers of fluidized bed boilers

    International Nuclear Information System (INIS)

    A CFD simulation was carried out for the platen superheater placed in the combustion chamber of the CFB boiler. Velocity, pressure, and temperature of the steam as well as the temperature of the tube wall with the complex cross section were computed using the ANSYS/CFX software. The direct and inverse problems were solved. In the first inverse problem, the heat transfer coefficient on the flue gas side was determined based on the measured steam temperature at the inlet and outlet of the three pass steam superheater. In the second inverse problem, the inlet steam temperature and the heat transfer coefficient on the flue gas side were estimated using measured steam temperatures at selected locations of the superheater. The first inverse problem was solved iteratively using the secant method. The Levenberg-Marquardt method was used to solve the second inverse problem. At every iteration step, a direct conjugate heat transfer problem was solved using the ANSYS/CFX software. -- Highlights: • Platen superheater in Circulating Fluidized Bed Boilers (CFB Boilers) was modeled using CFD simulation. • Method for determining flue-gas side heat transfer coefficient was developed. • Two inverse heat transfer problems were solved

  15. Characterization and Quantification of Deposits Buildup and Removal in Biomass Suspension-Fired Boilers

    DEFF Research Database (Denmark)

    Shafique Bashir, Muhammad; Jensen, Peter Arendt; Frandsen, Flemming;

    2010-01-01

    Utilization of biomass as wood or straw in large suspension­fired boilers is an efficient method to reduce the use of fossil fuels consumption and to reduce the net CO2 formation. However, the presence of chlorine and alkali metals in biomass (straw) generate ash with a low melting point and induce...... uptake reduction, fly ash and deposit characteristics, and deposit removal by using an advanced online deposit probe in a suspension­fired boiler using wood and straw pellets as fuel. The influence of fuel type and probe exposure time on the ash deposition rate, the heat uptake, the fly ash and deposit...... small in the tube bank region (flue gas temperature, 550­605 oC) during pure wood­firing. It was found that during suspension­firing of pure straw at low boiler load, the overall weight uptake is comparable with grate­firing, even though the amount of fly ash generated was significantly higher during...

  16. 蒸汽侧氧化膜对锅炉T91钢管蠕变断裂寿命的影响%Effects of Steam-side Oxide Scale on Creep Rupture Life of T91 Boiler Steel Tubes

    Institute of Scientific and Technical Information of China (English)

    边彩霞; 周克毅; 朱正林; 胥建群

    2013-01-01

    A calculation model was built up for the creep rupture life of T91 steel tubes,with which the effects of steam-side oxide scale on the creep rupture life were analyzed quantitatively from the aspects of temperature and equivalent stress,while a comparison made to the calculation results obtained under different conditions of heat flux and tube size.Results show that the increase of metal temperature resulted from steam-side oxide scale is the main cause of creep rupture life reduction,and the rise of equivalent stress is the secondary one; a parabolic relationship exists between the reduction of creep rupture life and the thickness of steam-side oxide scale; the effect of steam-side oxide scale on the creep rupture life intensifies with the rise of heat flux; the steam-side oxide scale has greater influence on creep rupture life of tubes with smaller outside diameter but larger wall thickness.%建立了电站锅炉T91钢管蠕变断裂寿命计算模型,定量分析了蒸汽侧管壁温度和等效应力对T91受热管蠕变断裂寿命的影响,并对不同热负荷、不同尺寸受热管的计算结果进行了比较.结果表明:蒸汽侧氧化膜导致管壁温度升高是缩短部件蠕变断裂寿命的主要原因,等效应力增大是次要原因;受热管的蠕变断裂寿命随蒸汽侧氧化膜厚度的增加呈抛物线缩短;随管子热负荷的增加,蒸汽侧氧化膜对受热管蠕变断裂寿命的影响程度加剧;蒸汽侧氧化膜对外径较小的厚壁管子蠕变断裂寿命的影响较大.

  17. Evaluation of the technological feasibility, and cost of selected control alternatives necessary to meet the proposed Ohio SO/sub 2/ regulations for industrial boilers and processes. Volume I. Youngstown Sheet and Tube Company, Campbell Works - coke oven gas desulfurization. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hall, R.R.; Stanley, W.T.; Sahagian, J.

    1976-06-01

    This report presents an evaluation by the GCA Corporation, GCA/Technology Division, of the technological feasibility and cost of complying with the proposed Ohio sulfur dioxide regulation (40 FR 52410, November 10, 1975) at Youngstown Sheet and Tube's Campbell Works. The final USEPA Sulfur Dioxide Strategy for the State of Ohio Technical Support Documents, Vol. I and II, (EPA 905/2-76-002) may be obtained from NTIS. The Campbell Works was an example of a by-product coke oven facility. After collecting necessary site and source specific data by means of a plant visit, the technical feasibility of the vacuum carbonate, Dravo Firma, Carl Still, Sulfiban and Holmes Stretford processes were evaluated. Capital and operating costs are presented for the latter three systems.

  18. 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

  19. Super-heater tube failure due to overheating when using bagasse as fuel

    Directory of Open Access Journals (Sweden)

    John Jairo Coronado Marín

    2010-04-01

    Full Text Available A super-heater’s boiler tubes presented external longitudinal cracks. The tubes’ external surfaces presented a reddish-white layer consisting of paraffin chains: CH, functional groups: CO, NH and sulphur compounds. This brittle layer prevented heat transfer, thereby causing increased tube temperature. Creep led to failure due to long-term overheating. The steel tubes’ microstructure presented grain growth, cementite globulisation and intergranular cracks on the external surface. The foregoing observations support microstructure deterioration facilitated by the presence of unsuitable super-heater tube material when just using bagasse as fuel.

  20. Physical and Numerical Analysis of Extrusion Process for Production of Bimetallic Tubes

    Energy Technology Data Exchange (ETDEWEB)

    Misiolek, W.Z.; Sikka, V.K.

    2006-08-10

    Bimetallic tubes are used for very specific applications where one of the two metals provides strength and the other provides specific properties such as aqueous corrosion and carburization, coking resistance, and special electrical and thermal properties. Bimetallic tubes have application in pulp and paper industry for heat-recovery boilers, in the chemical industry for ethylene production, and in the petrochemical industry for deep oil well explorations. Although bimetallic tubes have major applications in energy-intensive industry, they often are not used because of their cost and manufacturing sources in the United States. This project was intended to address both of these issues.

  1. NOx EMISSIONS PRODUCED WITH COMBUSTION OF POWDER RIVER BASIN COAL IN A UTILITY BOILER

    Energy Technology Data Exchange (ETDEWEB)

    John S. Nordin; Norman W. Merriam

    1997-04-01

    The objective of this report is to estimate the NOx emissions produced when Powder River Basin (PRB) coal is combusted in a utility boiler. The Clean Air Act regulations specify NOx limits of 0.45 lb/mm Btu (Phase I) and 0.40 lb/mm Btu (Phase II) for tangentially fired boilers, and 0.50 lb/mm 13tu (Phase II) and 0.46 lb/mm Btu (Phase II) for dry-bottom wall-fired boilers. The Clean Air Act regulations also specify other limits for other boiler types. Compliance for Phase I has been in effect since January 1, 1996. Compliance for Phase II goes into effect on January 1, 2000. Emission limits are expressed as equivalent NO{sub 2} even though NO (and sometimes N{sub 2}O) is the NOx species emitted during combustion. Regulatory agencies usually set even lower NOx emission limits in ozone nonattainment areas. In preparing this report, Western Research Institute (WRI) used published test results from utilities burning various coals, including PRB coal, using state-of-the art control technology for minimizing NOx emissions. Many utilities can meet Clean Air Act NOx emission limits using a combination of tight combustion control and low-NOx burners and by keeping furnaces clean (i.e., no slag buildup). In meeting these limits, some utilities also report problems such as increased carbon in their fly ash and excessive furnace tube corrosion. This report discusses utility experience. The theory of NOx emission formation during coal combustion as related to coal structure and how the coal is combusted is also discussed. From this understanding, projections are made for NOx emissions when processed PRB coal is combusted in a test similar to that done with other coals. As will be shown, there are a lot of conditions for achieving low NOx emissions, such as tight combustion control and frequent waterlancing of the furnace to avoid buildup of deposits.

  2. Factors in the selection of broiler tube materials for a civil fast reactor

    International Nuclear Information System (INIS)

    This paper briefly considers some of the factors which must be balanced in the selection of a boiler tube material for a Civil Fast Reactor. The merits and possible demerits of low alloy ferritic steels and the austenitic Alloy 800 are compared with respect to waterside corrosion resistance, mechanical properties, fabrication and weldability and possible effects of exposure to the sodium environment under normal and fault conditions. It is pointed out that although there is operational experience of most of the materials in boiler superheater applications there is little or none in evaporative regimes. (author)

  3. Flow Induced Acoustic Resonance in In-line Tube Banks

    Institute of Scientific and Technical Information of China (English)

    Hiromitsu Hamakawa; Tohru Fukano; Eiichi Nishida; Yoshikazu Satou

    2006-01-01

    In the present paper the attention is focused on the relation between vortex shedding phenomena and acoustic resonance which occurred in the two-dimensional model of boiler. There were tube banks with in-line arrangement for small tube pitch ratio. We measured the sound pressure level, the phase delay of acoustic pressures, the spectrum of velocity fluctuation and the gap velocity. As a result, we found two peak frequencies of sound pressure level with different Strouhal numbers St, mainly about 0.26 and 0.52. The noise of St=0.26 was the resonance of transverse mode and St=0.52 was longitudinal mode. The vortex shedding of St=0.15 was generated inside the tube banks without acoustic resonance. As gap velocity increased, we observed that the peak level of spectrum was weak and broad-banded. The onset velocity of the acoustic resonance of longitudinal mode was lower than that of transverse mode.

  4. Low Cost Polymer heat Exchangers for Condensing Boilers

    Energy Technology Data Exchange (ETDEWEB)

    Butcher, Thomas [Brookhaven National Lab. (BNL), Upton, NY (United States); Trojanowski, Rebecca [Brookhaven National Lab. (BNL), Upton, NY (United States); Wei, George [Brookhaven National Lab. (BNL), Upton, NY (United States); Worek, Michael [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-09-30

    Work in this project sought to develop a suitable design for a low cost, corrosion resistant heat exchanger as part of a high efficiency condensing boiler. Based upon the design parameters and cost analysis several geometries and material options were explored. The project also quantified and demonstrated the durability of the selected polymer/filler composite under expected operating conditions. The core material idea included a polymer matrix with fillers for thermal conductivity improvement. While the work focused on conventional heating oil, this concept could also be applicable to natural gas, low sulfur heating oil, and biodiesel- although these are considered to be less challenging environments. An extruded polymer composite heat exchanger was designed, built, and tested during this project, demonstrating technical feasibility of this corrosion-resistant material approach. In such flue gas-to-air heat exchangers, the controlling resistance to heat transfer is in the gas-side convective layer and not in the tube material. For this reason, the lower thermal conductivity polymer composite heat exchanger can achieve overall heat transfer performance comparable to a metal heat exchanger. However, with the polymer composite, the surface temperature on the gas side will be higher, leading to a lower water vapor condensation rate.

  5. Guide to Low-Emission Boiler and Combustion Equipment Selection

    Energy Technology Data Exchange (ETDEWEB)

    Oland, CB

    2002-05-06

    Boiler owners and operators who need additional generating capacity face a number of legal, political, environmental, economic, and technical challenges. Their key to success requires selection of an adequately sized low-emission boiler and combustion equipment that can be operated in compliance with emission standards established by state and federal regulatory agencies. Recognizing that many issues are involved in making informed selection decisions, the U.S. Department of Energy (DOE), Office of Industrial Technologies (OIT) sponsored efforts at the Oak Ridge National Laboratory (ORNL) to develop a guide for use in choosing low-emission boilers and combustion equipment. To ensure that the guide covers a broad range of technical and regulatory issues of particular interest to the commercial boiler industry, the guide was developed in cooperation with the American Boiler Manufacturers Association (ABMA), the Council of Industrial Boiler Owners (CIBO), and the U.S. Environmental Protection Agency (EPA). The guide presents topics pertaining to industrial, commercial, and institutional (ICI) boilers. Background information about various types of commercially available boilers is provided along with discussions about the fuels that they burn and the emissions that they produce. Also included are discussions about emissions standards and compliance issues, technical details related to emissions control techniques, and other important selection considerations. Although information in the guide is primarily applicable to new ICI boilers, it may also apply to existing boiler installations.

  6. Ash Deposit Formation and Removal in a Straw and Wood Suspension-Fired Boiler

    DEFF Research Database (Denmark)

    Shafique Bashir, Muhammad; Jensen, Peter Arendt; Frandsen, Flemming;

    limited to two weeks when 100% straw was fired due to ash deposition in the superheater region that has tube spacing specified for coal-firing (113mm). A series of 3-5 days deposit probe experiments were conducted utilizing 35 to 100% straw with wood on mass basis. The applied deposit probe was water and...... superheater region (1st draught, flue gas temperature, 820-865 °C) and in the tube bank region (2nd draught, flue gas temperature, 580-605 oC). The percentage of ash in the applied straw and wood was 5.9 % and 3.3 %, while the K contents were 0.81% and 0.09% respectively. During 35% straw share, the initial......Utilization of biomass on large suspension-fired boilers is a potentially efficient method to reduce net CO2 emissions and reduce the consumption of fossil fuels. However, ash deposit formation on heat transfer surfaces may cuase operational problems and in severe cases lead to boiler stop and...

  7. Design, construction and operating experience of boilers at Wylfa power station

    International Nuclear Information System (INIS)

    The report will describe the boilers, but will emphasise the problems encountered and the solutions. The boilers are 'once through' with start up drums. Some redundancy was provided but this advantage was lost due to downrating of gas temperature. The boilers are carbon steel suspended plattens (992 per reactor) tightly packed in the annular space between the core shielding and the spherical wall of the pressure vessel. This construction denies access to repair tube leaks. when a leak occurs the faulty platten has to be plugged off. This is done with the reactor at 60% power. The process will be described. Reactor 1 commenced operation in 1971, Reactor 2 in June 1971. Between 1972 and May 1984 21 leaks occurred which resulted in a major shutdown for investigation. This revealed the leaks were caused by gas flow induced vibration resulting in fretting of tubes in clips. Restraints and additional clamps were fitted. This has been successful but the modifications were extensive and in very difficult working conditions, the Reactor being shut down until May 1976. A family of leaks adjacent to personnel access ways commenced in Reactor 1 in 1975 which was later identified as erosion/corrosion on the water/steam side caused by the feed flow instability. This problem is common to both Reactors. Various modifications have been applied. Redistribution of feed flow using orifice plates and ferrules was only temporarily successful. Following extensive rig testing the feed water has been dosed with amino methyl proponal (AMP) since September 1983 with an immediate and sustained reduction in the leak rate. The amine provides protection through the steam/water phase. Rig testing continues to attain a better understanding of the erosion/corrosion. (author)

  8. Analog-experiment analysis of ash-deposition monitoring model of boiler economizers in power plants

    Institute of Scientific and Technical Information of China (English)

    CHENG Wei-liang; XIA Guo-dong; XU Shou-chen

    2005-01-01

    Ash deposition is a form of particulate fouling, and appears usually in boiler economizers. The ash deposition increases capital expenditure, energy input and maintenance costs. An analog experiment for monitoring ash deposition was performed from the analogous objective of a 410 t/h boiler economizer to verify the rationality and reliability of the ash-deposition-monitoring model presented in order to increase the security and economy in economizer running. The analog experiment platform is a tube-shell exchanger that conforms well to the conditions of a self-modeling area. The analog flue gas in the shell side is the heated air mixed with ash,and in the tube side the fluid is water heated by the flue gas. The fluid state in the water side and the flue gas side follows the second self-modeling area. A 4-factor-3 level orthogonal table was used to schedule 9 operation conditions of orthogonal experiment, with the 4 factors being heat power, flue gas velocity, ashes grain diameter and adding ashes quantity while the three levels are different values due to different position classes in every factor. The ash deposition thermal resistances is calculated by the model with the measure parameters of temperature and pressure drop. It shows that the values of the ash deposition thermal resistances gradually increase up to a stable state. And the experimental results are reliable by F testing method at α = 0. 001. Therefore, the model can be applied in online monitoring of ash deposition in a boiler economizers in power plants and provides scientific decision on ash deposition prediction and sootblowing.

  9. Performance of high-velocity oxy-fuel-sprayed chromium carbide-nickel chromium coating in an actual boiler environment of a thermal power plant

    Energy Technology Data Exchange (ETDEWEB)

    Sidhu, T.S.; Prakash, S.; Agrawal, R.D. [Industrial Technology Institute, Roorkee (India)

    2007-09-15

    The present study aims to evaluate the performance of a high-velocity oxy-fuel (HVOF)-sprayed Cr{sub 3}C{sub 2}-NiCr (chromium carbide-nickel chromium) coating on a nickel-based super-alloy in an actual industrial environment of a coal-fired boiler, with the objective to protect the boiler super-heater and reheater tubes from hot corrosion. The tests were performed in the platen super heater zone of a coal-fired boiler for 1,000 h at 900 degrees C under cyclic conditions. The Cr{sub 3}C{sub 2}-NiCr coating imparted the necessary protection to the nickel-based super alloy in the given environment. The dense and flat splat structure of the coating, and the formation of oxides of chromium and nickel and their spinels, might have protected the substrate super alloy from the inward permeation of corrosive species.

  10. Neural Tube Defects

    Science.gov (United States)

    Neural tube defects are birth defects of the brain, spine, or spinal cord. They happen in the first month ... that she is pregnant. The two most common neural tube defects are spina bifida and anencephaly. In spina bifida, ...

  11. Tracheostomy tube - speaking

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000465.htm Tracheostomy tube - speaking To use the sharing features on ... are even speaking devices that can help you. Tracheostomy Tubes and Speaking Air passing through vocal cords ( ...

  12. 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. PMID:23573684

  13. Recovery boiler model; Soodakattilan kehitystyoe III

    Energy Technology Data Exchange (ETDEWEB)

    Janka, K.; Ylitalo, M.; Sundstroem, K.; Helke, R.; Heinola, M. [Kvaerner Pulping Oy, Tampere (Finland)

    1997-10-01

    The recovery boiler model was further tested and developed. At this moment the model includes submodels for: droplet drying, pyrolysis, char burning, gas burning and for droplet trajectory. During 1996 the formation of CH{sub 4} during pyrolysis and release of sulfur was included to the model. Further the formation of NO from fuel nitrogen and formation of thermal- NO were included to the model using Arrhenius type reaction rate equations. The calculated results are realistic and the model is used as a tool to find out methods to increase the efficiency and availability and decrease the emissions. Analysing the results of the earlier field study of 8 boilers showed that the furnace heat load, fuming rate, find the black liquor composition have influence on the enrichment of the potassium to the fly ash. (orig.)

  14. Study of Corrosion in a Biomass Boiler

    OpenAIRE

    Berlanga, C.; Ruiz, J. A.

    2013-01-01

    Biomass plants, apart from producing energy, help to reduce CO2(g) emissions. One of the biggest problems for their development is superheater corrosion due to fuel corrosivity, especially of the straw. This limits both the temperature of the vapour and also the effectiveness of the plant. In order to know more about the reactions which happen inside the boiler of biomass, thermodynamic calculations using software (HSC Chemistry) have been carried out. Field tests have been carried out in the...

  15. Boiler Modelling of Simple Combustion Processes

    OpenAIRE

    Radovan Nosek; Jozef Jandacka; Andrzej Szlek

    2012-01-01

    The aim of the work is to investigate coal combustion in fixed bed reactor. The experimental results were worked out in the form of approximation functions describing gas composition at the exit of fixed bed reactor. Furthermore, developed functions were applied for defining the boundary conditions at the interface between the fixed bed and gas phase using FLUENT. The simulations of a domestic boiler have been done and the relative effects of different factors in CFD code were evaluated by se...

  16. Incidence of cancer among Norwegian boiler welders.

    OpenAIRE

    Danielsen, T E; Langård, S; Andersen, A.

    1996-01-01

    OBJECTIVES: The cancer incidence among 2957 boiler welders was investigated. The subjects were registered electrical welders from 1942 to 1981. A subcohort of 606 stainless steel welders was studied separately. METHODS: The investigation was a historical prospective cohort study based on a national registry. The loss of follow up was 4.9%. RESULTS: There were 625 deaths (659 expected). There were 269 cancer cases (264 expected). An excess of lung cancer was found; 50 cases v 37.5 expected. Th...

  17. Circulating fluidized bed boilers design and operations

    CERN Document Server

    Basu, Prabir

    1991-01-01

    This book provides practicing engineers and students with insight into the design and operation of circulating fluidized bed (CFB) boilers. Through a combination of theoretical concepts and practical experience, this book gives the reader a basic understanding of the many aspects of this subject.Important environmental considerations, including solid waste disposal and predicted emissions, are addressed individually in separate chapters. This book places an emphasis on combustion, hydrodynamics, heat transfer, and material issues, and illustrates these concepts with numerous examples of pres

  18. 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.

  19. Particulate emission abatement for Krakow boiler houses

    Energy Technology Data Exchange (ETDEWEB)

    Wysk, R.

    1995-12-31

    Among the many strategies for improving air quality in Krakow, one possible method is to adapt new and improved emission control technology. This project focuses on such a strategy. In order to reduce dust emissions from coal-fueled boilers, a new device called a Core Separator has been introduced in several boiler house applications. This advanced technology has been successfully demonstrated in Poland and several commercial units are now in operation. Particulate emissions from the Core Separator are typically 3 to 5 times lower than those from the best cyclone collectors. It can easily meet the new standard for dust emissions which will be in effect in Poland after 1997. The Core Separator is a completely inertial collector and is based on a unique recirculation method. It can effectively remove dust particles below 10 microns in diameter, the so-called PM-10 emissions. Its performance approaches that of fabric filters, but without the attendant cost and maintenance. It is well-suited to the industrial size boilers located in Krakow. Core Separators are now being marketed and sold by EcoInstal, one of the leading environmental firms in Poland, through a cooperative agreement with LSR Technologies.

  20. 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

    2003-08-04

    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.

  1. Gastrostomy feeding tube - bolus

    Science.gov (United States)

    ... a gastrostomy tube. Delmar’s Fundamental and Advanced Nursing Skills . 2nd Ed. Albany, NY: Delmar Thomson Learning; 2003: 742-749. Simmons, Remmington R.The percutaneous endoscopic gastrostomy tube: a nurse's guide to PEG tubes. Medsurg Nurs . 2013 Mar- ...

  2. KER-2 tube history

    Energy Technology Data Exchange (ETDEWEB)

    Banister, W.C.

    1963-08-16

    Zirconium process tube No. 1986 was installed in KE Reactor tube channel No. 2864 on April 16, 1959. This report describes the history and the conditions to which it was exposed during its residence in the reactor. The tube was removed on May 31, 1963.

  3. 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.

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

    International Nuclear Information System (INIS)

    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

  5. Modelling, simulating and optimizing boiler heating surfaces and evaporator circuits

    DEFF Research Database (Denmark)

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

    2003-01-01

    A model for optimizing the dynamic performance of boiler have been developed. Design variables related to the size of the boiler and its dynamic performance have been defined. The object function to be optimized takes the weight of the boiler and its dynamic capability into account. As constraints...... for the optimization a dynamic model for the boiler is applied. Furthermore a function for the value of the dynamic performance is included in the model. The dynamic models for simulating boiler performance consists of a model for the flue gas side, a model for the evaporator circuit and a model for...... the drum. The dynamic model has been developed for the purpose of determining boiler material temperatures and heat transfer from the flue gas side to the water-/steam side in order to simulate the circulation in the evaporator circuit and hereby the water level fluctuations in the drum. The dynamic...

  6. The behavior of ash species in suspension fired biomass boilers

    DEFF Research Database (Denmark)

    Jensen, Peter Arendt

    to generate ash particles typically in the size range of 50 to 200 μm on biomass suspension fired power plant boilers. A fragmentation rate of fuel particles of 3 have been used to describe both the residual ash formation process in laboratory entrained flow reactors and in full scale boilers.A range...... coal fly ash with a high content of Si and Al isused as an additive on wood fired plants to reduce the problems with alkali salt de-activationof SCR catalysts. While the fundamental chemistry of the additives are well known detailed reaction models of the interaction of salts and additive particles......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...

  7. Investigation and Treatment of the Waste Heat Boiler Leakage in the CO Moderate Temperature Shift Unit%中变废锅泄漏的排查及处理

    Institute of Scientific and Technical Information of China (English)

    田红; 曹超; 吴娟

    2014-01-01

    Describe the tube and the tube sheet leakage of the waste heat boiler in the CO shift unit during it's operation , the leakage effects on the water desalination system , and the leakage investigation and treatment .%介绍了净化中变废热锅炉在运行中列管及管板泄漏,对脱盐水系统造成的影响,以及漏点排查及处理过程。

  8. 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

    build-up increased with the K-content of the fuel ash and fly ash for grate-fired boilers. For suspension-fired boilers, deposition rates are comparatively low for wood-firing and increase with increasing fuel straw shares. Shedding of deposits occurs by melting during straw-firing on a grate at high......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...... been examined. The firing technology and the fuel utilized influence the fly ash and deposit chemical composition. In grate-firing, K, Cl, and S are enriched in the fly ash compared to the fuel ash, while the fly ash in suspension-firing is relatively similar to the fuel ash. The chemical composition...

  9. Evaluation of surrogate boilers for steam generators. Final report

    International Nuclear Information System (INIS)

    Corrosion in PWR systems is a continuing problem that can result in significant expenditures for inspection, repair, and replacement of steam generators as well as for power replacement during outages. Model boilers operated in parallel to the steam generator may provide a useful tool for monitoring and studying steam generator corrosion and corrosion prevention processes. The potential benefits of such boilers as well as several conceptual boiler design alternatives are described, and approximate costs for fabrication and operation of such systems are presented

  10. Optimal Combustion Conditions for a Small-scale Biomass Boiler

    OpenAIRE

    Viktor Plaček; Cyril Oswald; Jan Hrdlička

    2012-01-01

    This paper reports on an attempt to achieve maximum efficiency and lowest possible emissions for a small-scale biomass boiler. This aim can be attained only by changing the control algorithm of the boiler, and in this way not raising the acquisition costs for the boiler. This paper describes the experimental facility, the problems that arose while establishing the facility, and how we have dealt with them. The focus is on discontinuities arising after periodic grate sweeping, and on finding t...

  11. Investigations of operation problems at a 200 MWe PF boiler

    OpenAIRE

    Peta Sandile; Toit Chris du; Naidoo Reshendren; Schmitz Walter; Jestin Louis

    2015-01-01

    To minimize oxides of nitrogen (NOx) emission, maximize boiler combustion efficiency, achieve safe and reliable burner combustion, it is crucial to master global boiler and at-the-burner control of fuel and air flows. Non-uniform pulverized fuel (PF) and air flows to burners reduce flame stability and pose risk to boiler safety by risk of reverse flue gas and fuel flow into burners. This paper presents integrated techniques implemented at pilot ESKOM power plants for the determination of glob...

  12. PERANCANGAN pH METER PADA BOILER HRSG BERBASIS ARDUINO

    OpenAIRE

    Yuliza .; Gatot Susanto

    2015-01-01

    Air merupakan zat yang sangat dibutuhkan pada setiap sektor industri, termasuk pemanfaatan untuk kebutuhan energi dan pemanasan. Kebutuhan energi dan pemanasan di industri umumnya dipenuhi dengan cara memanfaatkan steam yang dibangkitkan dalam suatu ketel (boiler). Air yang digunakan sebagai umpan boiler dapat diperoleh dari berbagai sumber yaitu danau, sungai, laut, maupun sumur. Kandungan  air ini sangat mempengaruhi Harga pH pada air umpan boiler, penting untuk diperhatikan untuk mencegah ...

  13. Review of structural design criteria for heat exchanger tube sheets

    International Nuclear Information System (INIS)

    Survey of various tube sheet design criteria was made in order to establish structural design criterion for the high-temperature tube sheet of the Intermediate Heat Exchanger of the Experimental Multipurpose VHTR. From this survey, it was found that there is no appropriate design criterion for the IHX high-temperature tube sheet among those tube sheet design criteria. However, the stress analysis method of tube sheet given in ASME Boiler and Pressure Vessel Code Section III Appendix A-8000 is considered to be useful, which is two dimensional stress analysis method by replacing the perforated region of tube sheet to the equivalent solid plate. Concerning this method given in A-8000, recently, T.Slot et al. have proposed more accurate effective elastic constants than those given in A-8000. Then, it was examined what degree of the difference there is between the stress analysis results obtained from the data given in A-8000 and those from the data proposed by T.Slot et al. (author)

  14. 21 CFR 868.5800 - Tracheostomy tube and tube cuff.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Tracheostomy tube and tube cuff. 868.5800 Section... (CONTINUED) MEDICAL DEVICES ANESTHESIOLOGY DEVICES Therapeutic Devices § 868.5800 Tracheostomy tube and tube cuff. (a) Identification. A tracheostomy tube and tube cuff is a device intended to be placed into...

  15. The behavior of ash species in suspension fired biomass boilers

    OpenAIRE

    Jensen, Peter Arendt

    2015-01-01

    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 reme...

  16. Relocation of boilers to Gulbene, Latvia. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-09-01

    This report describes the relocation of two coal-fired boilers from Hoeje-Taastrup, Denmark to the City of Gulbene, Latvia and the conversion of one of these boilers to combustion of wood chips. The selection of Gulbene DHE as recipient of the two boilers was made by the Danish Energy Agency. The selection was based on e feasibility study, `Small Boilers Fuel Conversion Study` prepared by the Consulting Engineering Company Birch and Krogeoe/Esbensen in 1994. The recommendations regarding the relocation and conversion of the former coal-fired boilers to use wood chips have been given in a study performed by dk-TEKNIK in the year 1994. The objectives of the Consultant`s project can be summarized as follows: Prequalification of Contractors for the boiler relocation; Preparation of Tender Documents for relocation of two formerly coal-fired boilers placed in Hoeje-Taastrup to Gulbene and conversion of the boilers to combustion of wood fuel; Evaluation and Contracting; Site supervision; Handing-over. The scope of the report describes the final reporting of the boiler relocation to Gulbene. This includes: The process of the relocation; Financial calculations; Experience gained through the project. (EG)

  17. 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.

  18. Thermal power of small scale manually fed boiler

    OpenAIRE

    Janić Todor V.; Igić Saša M.; Dedović Nebojša M.; Pavlović Darijan B.; Turan Jan J.; Sedlar Aleksandar D.

    2015-01-01

    This study reviews test results of the combustion of square soybean straw bales used as fuel in manually fed boiler with nominal thermal power of 120 kWth. The influence of the mass flow rate (180, 265, 350, 435, and 520 kg h-1) of inlet air and flue gas recirculation (0%, 16.5%, and 33%) fed to the boiler furnace was continuously monitored. Direct method was used for determination of the boiler thermal power. Correlation between boiler thermal power and ba...

  19. Between the boiler and buffer tank; Zwischen Kessel und Speicher

    Energy Technology Data Exchange (ETDEWEB)

    Ertmer, Katharina

    2013-08-06

    Some manufacturers offer new heating pump groups for return temperature raising for solid-fuel boilers. [German] Einige Hersteller bieten neue Heizungspumpengruppen zur Ruecklauftemperaturanhebung bei Festbrennstoffkesseln an.

  20. Thermomechanical finite element analysis of hot water boiler structure

    OpenAIRE

    Živković Dragoljub S.; Milčić Dragan S.; Banić Milan S.; Milosavljević Peđa M.

    2012-01-01

    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 pipe...

  1. 46 CFR 52.20-17 - Opening between boiler and safety valve (modifies PFT-44).

    Science.gov (United States)

    2010-10-01

    ... ENGINEERING POWER BOILERS Requirements for Firetube Boilers § 52.20-17 Opening between boiler and safety valve (modifies PFT-44). When a discharge pipe is used, it must be installed in accordance with the...

  2. 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.

  3. Fireside corrosion testing of candidate superheater tube alloys, coatings, and claddings - phase II

    Energy Technology Data Exchange (ETDEWEB)

    Blough, J.L.; Stanko, G.J. [Foster Wheeler Development Corp., Livingston, NJ (United States)

    1996-08-01

    In Phase I a variety of developmental and commercial tubing alloys and claddings were exposed to laboratory fireside corrosion testing simulating a superheater or reheater in a coal-fired boiler. Phase II (in situ testing) has exposed samples of 347, RA-8511, HR3C, 253MA, Fe{sub 3}Al + 5Cr, 310 modified, 800HT, NF 709, 690 clad, and 671 clad for over 10,000 hours to the actual operating conditions of a 250-MW coal-fired boiler. The samples were installed on an air-cooled, retractable corrosion probe, installed in the reheater cavity, and controlled to the operating metal temperatures of an existing and advanced-cycle coal-fired boiler. Samples of each alloy will be exposed for 4000, 12,000, and 16,000 hours of operation. The results will be presented for the metallurgical examination of the corrosion probe samples after 4000 hours of exposure.

  4. Heat exchanger tube tool

    International Nuclear Information System (INIS)

    Certain types of heat-exchangers have tubes opening through a tube sheet to a manifold having an access opening offset from alignment with the tube ends. A tool for inserting a device, such as for inspection or repair, is provided for use in such instances. The tool is formed by a flexible guide tube insertable through the access opening and having an inner end provided with a connector for connection with the opening of the tube in which the device is to be inserted, and an outer end which remains outside of the chamber, the guide tube having adequate length for this arrangement. A flexible transport hose for internally transporting the device slides inside of the guide tube. This hose is long enough to slide through the guide tube, into the heat-exchanger tube, and through the latter to the extent required for the use of the device. The guide tube must be bent to reach the end of the heat-exchanger tube and the latter may be constructed with a bend, the hose carrying anit-friction elements at interspaced locations along its length to make it possible for the hose to negotiate such bends while sliding to the location where the use of the device is required

  5. Reconstruction of industrial boiler type DKVR-13 aiming for combustion of waste materials from oil-yielding production

    International Nuclear Information System (INIS)

    One of the methods for improving of the energy efficiency is the use of a secondary energy resources such as waste products from industrial processes. In case of the oil extraction a great amount of waste product (sunflower shells) with a good thermal potential is available. During the industrial process from 100 kg raw material 15 kg shells are obtained. The combustion heat is about 1700 kJ/kg. The volatile compounds yield is 66.1%. An installation has been constructed intended to use the waste product from the extraction, consisting of: a water tube boiler with a steam capacity of 20 t/h and two PKM-12 type flue boilers and two DKVR 10-13 type water tube boilers. The DKVR 10-13 type boilers are designed for the production of 22.77 kg/s saturated steam with pressure 1.28 MPa and temperature 194oC. They have an unified constructional schemes with a two-drum evaporating system and a natural circulation. The furnace has a horizontally evaporation beam washed by the gas flux. The reconstruction is aimed to create condition for the use of the sunflower shells as a main fuel and the natural gas or other fuel as additional. The scheme is one using the sloping bed combustion. 70% of the steam production is due to the shells combustion. Calculations for the grid parameters have been done. An additional heater improves the efficiency with 4.5% and the expected annual fuel saving is 300 t. The introduction of hot air (165oC) provides both combustion and ecological benefits

  6. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... NEI YouTube Videos > NEI YouTube Videos: Amblyopia NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration ... Retinopathy of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia NEI on Twitter NEI on YouTube ...

  7. NEI You Tube Videos: Amblyopia

    Medline Plus

    Full Text Available ... YouTube Videos > NEI YouTube Videos: Amblyopia NEI YouTube Videos YouTube Videos Home Age-Related Macular Degeneration Amblyopia ... of Prematurity Science Spanish Videos Webinars NEI YouTube Videos: Amblyopia NEI on Twitter NEI on YouTube NEI ...

  8. Thermal resistance of steam-generator tube deposits under single-phase forced convection and flow-boiling heat transfer

    International Nuclear Information System (INIS)

    Degradation of the thermal performance of steam generators(SGs) is a serious problem in nuclear power stations throughout the world (Lovett and Dow, 1991). In pressurized-heavy-water reactors (PWHRs), the reduced thermal performance of the SGs is manifested by an increase of the primary coolant reactor inlet header temperature (RIHT). In pressurized-light-water reactors(PWRs), which operate with fixed primary coolant temperature, the loss of thermal performance is manifested by a reduction of the steam pressure. Degradation mechanisms that may contribute to the loss of SG thermal performance include: fouling of the boiler tube inner surfaces (primary-side fouling); fouling of the boiler tube outer surfaces (secondary-side fouling); divider and thermal plate leakage that causes the coolant to bypass either the SG or the integral preheater and fouling of the steam separators. The relative contribution of these various degradation mechanisms to the overall loss of thermal performance is still under investigation. Soulard et al. (1990) examined the relative contributions of tube bundle fouling, divider plate leakage, and thermal plate leakage to the increase in RIHT at the Point Lepreau Generating Station, and concluded that tube fouling contributes to a significant fraction of the loss of thermal performance. Corrosion products deposit on both the inner and outer surfaces of the boiler tubes. Thus a complete understanding of the reasons fro the loss of thermal performance and the development of strategies to mitigate this loss requires a knowledge of the thermal resistance of tube deposits under primary and secondary side heat transfer conditions. We present here the results of measurements of the thermal resistance of primary-side and secondary-side boiler tube deposits performed under single-phase forced convection and flow-boiling conditions, respectively. The results are discussed in terms of the physical properties of the deposit and the mode of heat transfer

  9. Thermomechanical CSM analysis of a superheater tube in transient state

    Science.gov (United States)

    Taler, Dawid; Madejski, Paweł

    2011-12-01

    The paper presents a thermomechanical computational solid mechanics analysis (CSM) of a pipe "double omega", used in the steam superheaters in circulating fluidized bed (CFB) boilers. The complex cross-section shape of the "double omega" tubes requires more precise analysis in order to prevent from failure as a result of the excessive temperature and thermal stresses. The results have been obtained using the finite volume method for transient state of superheater. The calculation was carried out for the section of pipe made of low-alloy steel.

  10. Pediatric cuffed endotracheal tubes

    Directory of Open Access Journals (Sweden)

    Neerja Bhardwaj

    2013-01-01

    Full Text Available Endotracheal intubation in children is usually performed utilizing uncuffed endotracheal tubes for conduct of anesthesia as well as for prolonged ventilation in critical care units. However, uncuffed tubes may require multiple changes to avoid excessive air leak, with subsequent environmental pollution making the technique uneconomical. In addition, monitoring of ventilatory parameters, exhaled volumes, and end-expiratory gases may be unreliable. All these problems can be avoided by use of cuffed endotracheal tubes. Besides, cuffed endotracheal tubes may be of advantage in special situations like laparoscopic surgery and in surgical conditions at risk of aspiration. Magnetic resonance imaging (MRI scans in children have found the narrowest portion of larynx at rima glottides. Cuffed endotracheal tubes, therefore, will form a complete seal with low cuff pressure of <15 cm H 2 O without any increase in airway complications. Till recently, the use of cuffed endotracheal tubes was limited by variations in the tube design marketed by different manufacturers. The introduction of a new cuffed endotracheal tube in the market with improved tracheal sealing characteristics may encourage increased safe use of these tubes in clinical practice. A literature search using search words "cuffed endotracheal tube" and "children" from 1980 to January 2012 in PUBMED was conducted. Based on the search, the advantages and potential benefits of cuffed ETT are reviewed in this article.

  11. An adaptation of the Citrosolv process to remove different types of deposits in boilers of a thermo-electric power plant

    International Nuclear Information System (INIS)

    During the inspection of a power station boiler was find out a high amount of scale/deposits on the tubes surface (> 100 mg/cm2). The scale/deposits constituents determined in chemical analysis, X-ray fluorescence and X-ray diffraction were iron, copper, calcium, magnesium, phosphorus and silicon. A chemical cleaning based on a small change of Citrosolv process, was used to remove those scale/deposits with sucess. (Author)

  12. Crack Testing and Treatment of Steam Boiler Smoke Pipe%蒸汽锅炉烟管裂纹检测及分析处理

    Institute of Scientific and Technical Information of China (English)

    陈迪翔

    2014-01-01

    This paper introduces crack cause, testing method and treatment of DZG4-1.25-MA horizontal water-fire tube wood steam boiler third return flue gas entrance pipe end .%介绍DZG4-1.25-MA卧式水火管燃木柴蒸汽锅炉第三回程烟气入口管端裂纹的检测方法、裂纹产生原因分析及处理。

  13. 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. PMID:23552243

  14. Nuclear reactors with auxiliary boiler circuit

    International Nuclear Information System (INIS)

    A gas-cooled nuclear reactor has a main circulatory system for the gaseous coolant incorporating one or more main energy converting units, such as gas turbines, and an auxiliary circulatory system for the gaseous coolant incorporating at least one steam generating boiler arranged to be heated by the coolant after its passage through the reactor core to provide steam for driving an auxiliary steam turbine, such an arrangement providing a simplified start-up procedure also providing emergency duties associated with long term heat removal on reactor shut down

  15. Selecting Actuator Configuration for a Benson Boiler

    DEFF Research Database (Denmark)

    Kragelund, Martin Nygaard; Leth, John-Josef; Wisniewski, Rafal

    2009-01-01

    This paper addresses the problem of an optimal actuator configuration in an economic perspective. The objective is to minimize the economical cost of operating a given plant. Functionals encapsulating information of the business objectives given the different actuators has been established...... with particular focus on a boiler in a power plant operated by DONG Energy - a Danish energy supplier. The problem has been reformulated using mathematic notions from economics. The selection of actuator configuration has been limited to the fuel system which in the considered plant consists of three different...

  16. Reactive leaching of recovery boiler fly ash

    OpenAIRE

    Frigård, Antti

    2016-01-01

    This thesis studied a new CaO leaching method for chloride and potassium removal from recovery boiler fly ash. The concept of this method is to use calcium oxide (or calcium hydroxide) as an additive in the leaching stage in order to ease the subsequent solid-liquid separation. CaO leaching has several benefits over traditional leaching process which uses sulphuric acid as an additive: CaO does not include sulphur that would affect the mills sulphur sodium balance, CaO is readily available in...

  17. 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.

  18. 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.

  19. 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...

  20. 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...

  1. NOX EMISSION FACTORS FOR WOOD-FIRED BOILERS

    Science.gov (United States)

    The report gives results of a review of NOx emission data from 14 wood-fired boilers. Types of wood used as fuel included sawdust, chips, shavings, edgings, bark, and other processing residues. Boilers tested ranged in size from 1.5 to 67 MW (4,500 to 200,000 lb steam/hr). The ma...

  2. Quality assurance in fabrication of boilers and pressure vessels

    International Nuclear Information System (INIS)

    Quality assurance for safety and reliability of boilers and pressure vessels is a systematic approach involving various stages right from material identification to final stages of testing, transportation and storage before commissioning. This paper brings out various quality . Assurance aspects to be implemented by manufacturers of boilers and pressure vessels. 1 fig

  3. Water Boiler Change-Over in Mini-TPP Mode

    OpenAIRE

    B. A. Bayrashevsky

    2014-01-01

    The paper considers water boiler modernization by its change-over in mini-TPP mode with an expansion tank and a heating turbine of small capacity.  A software complex permitting to evaluate competitive ability of such water boiler modernization in comparison with a cogeneration plant.

  4. Water Boiler Change-Over in Mini-TPP Mode

    Directory of Open Access Journals (Sweden)

    B. A. Bayrashevsky

    2014-08-01

    Full Text Available The paper considers water boiler modernization by its change-over in mini-TPP mode with an expansion tank and a heating turbine of small capacity.  A software complex permitting to evaluate competitive ability of such water boiler modernization in comparison with a cogeneration plant.

  5. Evaluation of erosion-oxidation and ash deposition in the convective section of an industrial watertube boiler retrofitted to fire coal-water fuel

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Jianyang; Walsh, P.M.; Miller, B.G.; Scaroni, A.W. [Pennsylvania State Univ., University Park, PA (United States)

    1994-12-31

    The feasibility of directly firing coal-water fuel in an oil-designed industrial watertube boiler is being determined for possible deployment at Department of Defense facilities. Erosion of carbon steel by particles and deposition of ash were measured in the convective section of the boiler while cofiring coal-water fuel and natural gas. Erosion was enhanced by directing a small jet of nitrogen, air, or oxygen toward the surface of a test coupon mounted on an air-cooled tube. The temperature and oxygen dependencies of the erosion rate were explained by a model for simultaneous erosion and oxidation. Extrapolation, using the experimentally determined coefficients for metal and oxide erosion, provided estimates of the erosion rate as functions of the gas velocity and angular position about the circumference of a heat exchanger tube in the convective section of the boiler. Under the conditions of metal temperature, oxygen concentration in the gas, particle size, and particle loading investigated, erosion of carbon steel is expected to be slower than 0.05 {mu}m/hour when the gas velocity in the convection section is less than approximately 8 m/s. A measurement in the convective section at 4 m/s gas velocity showed a pattern of ash deposits covering the circumference at positions on the tube surface where no erosion is predicted.

  6. Tubing weld cracking test

    International Nuclear Information System (INIS)

    A tubing weld cracking (TWC) test was developed for applications involving advanced austenitic alloys (such as modified 800H and 310HCbN). Compared to the Finger hot cracking test, the TWC test shows an enhanced ability to evaluate the crack sensitivity of tubing materials. The TWC test can evaluate the cracking tendency of base as well as filter materials. Thus, it is a useful tool for tubing suppliers, filler metal producers and fabricators

  7. 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.)

  8. Categorising YouTube

    OpenAIRE

    Thomas Mosebo Simonsen

    2011-01-01

    This article provides a genre analytical approach to creating a typology of the User Generated Content (UGC) of YouTube. The article investigates the construction of navigation processes on the YouTube website. It suggests a pragmatic genre approach that is expanded through a focus on YouTube’s technological affordances. Through an analysis of the different pragmatic contexts of YouTube, it is argued that a taxonomic understanding of YouTube must be analysed in regards to the vacillation of a...

  9. Calibrations of photomultiplier tubes

    International Nuclear Information System (INIS)

    The experimental methods for calibration photomultiplier tubes used in the multichannel fast-pulse-detection system of Thomson scattering measurements for nuclear fusion devices is reported. The most important parameters of the photomultiplier tubes to be calibrated include: linearity of output electric signals to input light signals, response time of pulsed light, spectral response, absolute responsibility, and sensitivity as a function of the chain voltage. The calibrations of all these parameters are carried out by using EMI 9558 B and RCA 7265 photomultiplier tubes respectively. The experimental methods presented in the paper are common to those quantitative measurements that require phomultiplier tubes as detectors

  10. Composite Pulse Tube

    Science.gov (United States)

    Martin, Jerry L.; Cloyd, Jason H.

    2007-01-01

    A modification of the design of the pulse tube in a pulse-tube cryocooler reduces axial thermal conductance while preserving radial thermal conductance. It is desirable to minimize axial thermal conductance in the pulse-tube wall to minimize leakage of heat between the warm and cold ends of the pulse tube. At the same time, it is desirable to maximize radial thermal conductance at the cold end of the pulse tube to ensure adequate thermal contact between (1) a heat exchanger in the form of a stack of copper screens inside the pulse tube at the cold end and (2) the remainder of the cold tip, which is the object to which the heat load is applied and from which heat must be removed. The modified design yields a low-heat-leak pulse tube that can be easily integrated with a cold tip. A typical pulse tube of prior design is either a thin-walled metal tube or a metal tube with a nonmetallic lining. It is desirable that the outer surface of a pulse tube be cylindrical (in contradistinction to tapered) to simplify the design of a regenerator that is also part of the cryocooler. Under some conditions, it is desirable to taper the inner surface of the pulse tube to reduce acoustic streaming. The combination of a cylindrical outer surface and a tapered inner surface can lead to unacceptably large axial conduction if the pulse tube is made entirely of metal. Making the pulse-tube wall of a nonmetallic, lowthermal- conductivity material would not solve the problem because the wall would not afford the needed thermal contact for the stack of screens in the cold end. The modified design calls for fabricating the pulse tube in two parts: a longer, nonmetallic part that is tapered on the inside and cylindrical on the outside and a shorter, metallic part that is cylindrical on both the inside and the outside. The nonmetallic part can be made from G-10 fiberglass-reinforced epoxy or other low-thermal-conductivity, cryogenically compatible material. The metallic part must have high

  11. Manual tube welding torch

    International Nuclear Information System (INIS)

    In a welding torch which fits over a tube intermediate the ends thereof for welding the juncture between the tube and a boss on the back side of a tube plate, a split housing encloses a tungsten electrode, a filler wire duct and a fiber optic bundle arranged to observe the welding process. A shielding gas duct is provided in the housing. A screw is provided for setting electrode/work distance. Difficult remote tube welding operations can be performed with the apparatus. (author)

  12. Steam generator tube performance

    International Nuclear Information System (INIS)

    A survey of steam generator operating experience for 1986 has been carried out for 184 pressurized water and pressurized heavy-water reactors, and 1 water-cooled, graphite-moderated reactor. Tubes were plugged at 75 of the reactors (40.5%). In 1986, 3737 tubes were plugged (0.14% of those in service) and 3148 tubes were repaired by sleeving. A small number of reactors accounted for the bulk of the plugged tubes, a phenomenon consistent with previous years. For 1986, the available tubesheet sludge data for 38 reactors has been compiled into tabular form, and sludge/deposit data will be incorporated into all future surveys

  13. BOILER MATERIALS FOR ULTRASUPERCRITICAL COAL POWER PLANTS

    Energy Technology Data Exchange (ETDEWEB)

    R. Viswanathan; K. Coleman; J. Shingledecker; J. Sarver; G. Stanko; M. Borden; W. Mohn; S. Goodstine; I. Perrin

    2005-08-01

    The U.S. Department of Energy (DOE) and the Ohio Coal Development Office (OCDO) have recently initiated a project aimed at identifying, evaluating, and qualifying the materials needed for the construction of the critical components of coal-fired boilers capable of operating at much higher efficiencies than current generation of supercritical plants. This increased efficiency is expected to be achieved principally through the use of ultrasupercritical steam conditions (USC). A limiting factor in this can be the materials of construction. The project goal is to assess/develop materials technology that will enable achieving turbine throttle steam conditions of 760 C (1400 F)/35 MPa (5000 psi). This goal seems achievable based on a preliminary assessment of material capabilities. The project is further intended to build further upon the alloy development and evaluation programs that have been carried out in Europe and Japan. Those programs have identified ferritic steels capable of meeting the strength requirements of USC plants up to approximately 620 C (1150 F) and nickel-based alloys suitable up to 700 C (1300 F). In this project, the maximum temperature capabilities of these and other available high-temperature alloys are being assessed to provide a basis for materials selection and application under a range of conditions prevailing in the boiler. This report provides a quarterly status report for the period of April 1 to June 30, 2005.

  14. Boiler Materials for Ultrasupercritical Coal Power Plants

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-04-21

    The U.S. Department of Energy (DOE) and the Ohio Coal Development Office (OCDO) have recently initiated a project aimed at identifying, evaluating, and qualifying the materials needed for the construction of the critical components of coal-fired boilers capable of operating at much higher efficiencies than current generation of supercritical plants. This increased efficiency is expected to be achieved principally through the use of ultrasupercritical steam conditions (USC). The project goal initially was to assess/develop materials technology that will enable achieving turbine throttle steam conditions of 760 C (1400 F)/35 MPa (5000 psi), although this goal for the main steam temperature had to be revised down to 732 C (1350 F), based on a preliminary assessment of material capabilities. The project is intended to build further upon the alloy development and evaluation programs that have been carried out in Europe and Japan. Those programs have identified ferritic steels capable of meeting the strength requirements of USC plants up to approximately 620 C (1150 F) and nickel-based alloys suitable up to 700 C (1300 F). In this project, the maximum temperature capabilities of these and other available high-temperature alloys are being assessed to provide a basis for materials selection and application under a range of conditions prevailing in the boiler. This report provides a quarterly status report for the period of July 1 to September 30, 2004.

  15. BOILER MATERIALS FOR ULTRASUPERCRITICAL COAL POWER PLANTS

    Energy Technology Data Exchange (ETDEWEB)

    R. Viswanathan; K. Coleman; J. Shingledecker; J. Sarver; G. Stanko; M. Borden; W. Mohn; S. Goodstine; I. Perrin

    2005-10-27

    The U.S. Department of Energy (DOE) and the Ohio Coal Development Office (OCDO) have recently initiated a project aimed at identifying, evaluating, and qualifying the materials needed for the construction of the critical components of coal-fired boilers capable of operating at much higher efficiencies than current generation of supercritical plants. This increased efficiency is expected to be achieved principally through the use of ultrasupercritical steam conditions (USC). A limiting factor in this can be the materials of construction. The project goal is to assess/develop materials technology that will enable achieving turbine throttle steam conditions of 760 C (1400 F)/35 MPa (5000 psi). This goal seems achievable based on a preliminary assessment of material capabilities. The project is further intended to build further upon the alloy development and evaluation programs that have been carried out in Europe and Japan. Those programs have identified ferritic steels capable of meeting the strength requirements of USC plants up to approximately 620 C (1150 F) and nickel-based alloys suitable up to 700 C (1300 F). In this project, the maximum temperature capabilities of these and other available high-temperature alloys are being assessed to provide a basis for materials selection and application under a range of conditions prevailing in the boiler. This report provides a quarterly status report for the period of July 1 to September 30, 2005.

  16. Boiler Materials for Ultrasupercritical Coal Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    R. Viswanathan; K. Coleman; J. Shingledecker; J. Sarver; G. Stanko; M. Borden; W. Mohn; S. Goodstine; I. Perrin

    2006-01-31

    The U.S. Department of Energy (DOE) and the Ohio Coal Development Office (OCDO) have recently initiated a project aimed at identifying, evaluating, and qualifying the materials needed for the construction of the critical components of coal-fired boilers capable of operating at much higher efficiencies than current generation of supercritical plants. This increased efficiency is expected to be achieved principally through the use of ultrasupercritical steam conditions (USC). A limiting factor in this can be the materials of construction. The project goal is to assess/develop materials technology that will enable achieving turbine throttle steam conditions of 760 C (1400 F)/35 MPa (5000 psi). This goal seems achievable based on a preliminary assessment of material capabilities. The project is further intended to build further upon the alloy development and evaluation programs that have been carried out in Europe and Japan. Those programs have identified ferritic steels capable of meeting the strength requirements of USC plants up to approximately 620 C (1150 F) and nickel-based alloys suitable up to 700 C (1300 F). In this project, the maximum temperature capabilities of these and other available high-temperature alloys are being assessed to provide a basis for materials selection and application under a range of conditions prevailing in the boiler. This report provides a quarterly status report for the period of October 1 to December 30, 2005.

  17. Boiler Materials for Ultrasupercritical Coal Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    R. Viswanathan; K. Coleman; J. Shingledecker; J. Sarver; G. Stanko; M. Borden; W. Mohn; S. Goodstine; I. Perrin

    2006-04-20

    The U.S. Department of Energy (DOE) and the Ohio Coal Development Office (OCDO) have recently initiated a project aimed at identifying, evaluating, and qualifying the materials needed for the construction of the critical components of coal-fired boilers capable of operating at much higher efficiencies than current generation of supercritical plants. This increased efficiency is expected to be achieved principally through the use of ultrasupercritical steam conditions (USC). A limiting factor in this can be the materials of construction. The project goal is to assess/develop materials technology that will enable achieving turbine throttle steam conditions of 760 C (1400 F)/35 MPa (5000 psi). This goal seems achievable based on a preliminary assessment of material capabilities. The project is further intended to build further upon the alloy development and evaluation programs that have been carried out in Europe and Japan. Those programs have identified ferritic steels capable of meeting the strength requirements of USC plants up to approximately 620 C (1150 F) and nickel-based alloys suitable up to 700 C (1300 F). In this project, the maximum temperature capabilities of these and other available high-temperature alloys are being assessed to provide a basis for materials selection and application under a range of conditions prevailing in the boiler. This report provides a quarterly status report for the period of January 1 to March 31, 2006.

  18. Boiler Materials for Ultrasupercritical Coal Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    R. Viswanathan; K. Coleman; J. Shingledecker; J. Sarver; G. Stanko; M. Borden; W. Mohn; S. Goodstine; I. Perrin

    2006-07-17

    The U.S. Department of Energy (DOE) and the Ohio Coal Development Office (OCDO) have recently initiated a project aimed at identifying, evaluating, and qualifying the materials needed for the construction of the critical components of coal-fired boilers capable of operating at much higher efficiencies than current generation of supercritical plants. This increased efficiency is expected to be achieved principally through the use of ultrasupercritical steam conditions (USC). A limiting factor in this can be the materials of construction. The project goal is to assess/develop materials technology that will enable achieving turbine throttle steam conditions of 760 C (1400 F)/35 MPa (5000 psi). This goal seems achievable based on a preliminary assessment of material capabilities. The project is further intended to build further upon the alloy development and evaluation programs that have been carried out in Europe and Japan. Those programs have identified ferritic steels capable of meeting the strength requirements of USC plants up to approximately 620 C (1150 F) and nickel-based alloys suitable up to 700 C (1300 F). In this project, the maximum temperature capabilities of these and other available high-temperature alloys are being assessed to provide a basis for materials selection and application under a range of conditions prevailing in the boiler. This report provides a quarterly status report for the period of April 1 to June 30, 2006.

  19. BOILER MATERIALS FOR ULTRASUPERCRITICAL COAL POWER PLANTS

    Energy Technology Data Exchange (ETDEWEB)

    R. Viswanathan; K. Coleman; J. Shingledecker; J. Sarver; G. Stanko; W. Mohn; M. Borden; S. Goodstine; I. Perrin

    2004-04-23

    The U.S. Department of Energy (DOE) and the Ohio Coal Development Office (OCDO) have recently initiated a project aimed at identifying, evaluating, and qualifying the materials needed for the construction of the critical components of coal-fired boilers capable of operating at much higher efficiencies than current generation of supercritical plants. This increased efficiency is expected to be achieved principally through the use of ultrasupercritical steam conditions (USC). The project goal initially was to assess/develop materials technology that will enable achieving turbine throttle steam conditions of 760 C (1400 F)/35 MPa (5000 psi), although this goal for the main steam temperature had to be revised down to 732 C (1350 F), based on a preliminary assessment of material capabilities. The project is intended to build further upon the alloy development and evaluation programs that have been carried out in Europe and Japan. Those programs have identified ferritic steels capable of meeting the strength requirements of USC plants up to approximately 620 C (1150 F) and nickel-based alloys suitable up to 700 C (1300 F). In this project, the maximum temperature capabilities of these and other available high-temperature alloys are being assessed to provide a basis for materials selection and application under a range of conditions prevailing in the boiler. This report provides a quarterly status report for the period of October 1 to December 30, 2003.

  20. BOILER MATERIALS FOR ULTRASUPERCRITICAL COAL POWER PLANTS

    Energy Technology Data Exchange (ETDEWEB)

    K. Coleman; R. Viswanathan; J. Shingledecker; J. Sarver; G. Stanko; W. Mohn; M. Borden; S. Goodstine; I. Perrin

    2004-01-23

    The U.S. Department of Energy (DOE) and the Ohio Coal Development Office (OCDO) have recently initiated a project aimed at identifying, evaluating, and qualifying the materials needed for the construction of the critical components of coal-fired boilers capable of operating at much higher efficiencies than current generation of supercritical plants. This increased efficiency is expected to be achieved principally through the use of ultrasupercritical steam conditions (USC). The project goal initially was to assess/develop materials technology that will enable achieving turbine throttle steam conditions of 760 C (1400 F)/35 MPa (5000 psi), although this goal for the main steam temperature had to be revised down to 732 C (1350 F), based on a preliminary assessment of material capabilities. The project is intended to build further upon the alloy development and evaluation programs that have been carried out in Europe and Japan. Those programs have identified ferritic steels capable of meeting the strength requirements of USC plants up to approximately 620 C (1150 F) and nickel-based alloys suitable up to 700 C (1300 F). In this project, the maximum temperature capabilities of these and other available high-temperature alloys are being assessed to provide a basis for materials selection and application under a range of conditions prevailing in the boiler. This report provides a quarterly status report for the period of October 1 to December 30, 2003.

  1. Boiler Materials For Ultrasupercritical Coal Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    R. Viswanathan; K. Coleman; J. Shingledecker; J. Sarver; G. Stanko; M. Borden; W. Mohn; S. Goodstine; I. Perrin

    2006-09-30

    The U.S. Department of Energy (DOE) and the Ohio Coal Development Office (OCDO) have recently initiated a project aimed at identifying, evaluating, and qualifying the materials needed for the construction of the critical components of coal-fired boilers capable of operating at much higher efficiencies than current generation of supercritical plants. This increased efficiency is expected to be achieved principally through the use of ultrasupercritical steam conditions (USC). A limiting factor in this can be the materials of construction. The project goal is to assess/develop materials technology that will enable achieving turbine throttle steam conditions of 760 C (1400 F)/35 MPa (5000 psi). This goal seems achievable based on a preliminary assessment of material capabilities. The project is further intended to build further upon the alloy development and evaluation programs that have been carried out in Europe and Japan. Those programs have identified ferritic steels capable of meeting the strength requirements of USC plants up to approximately 620 C (1150 F) and nickel-based alloys suitable up to 700 C (1300 F). In this project, the maximum temperature capabilities of these and other available high-temperature alloys are being assessed to provide a basis for materials selection and application under a range of conditions prevailing in the boiler. This report provides a quarterly status report for the period of July 1 to September 30, 2006.

  2. BOILER MATERIALS FOR ULTRASUPERCRITICAL COAL POWER PLANTS

    Energy Technology Data Exchange (ETDEWEB)

    R. Viswanathan; K. Coleman; J. Shingledecker; J. Sarver; G. Stanko; M. Borden; W. Mohn; S. Goodstine; I. Perrin

    2005-04-27

    The U.S. Department of Energy (DOE) and the Ohio Coal Development Office (OCDO) have recently initiated a project aimed at identifying, evaluating, and qualifying the materials needed for the construction of the critical components of coal-fired boilers capable of operating at much higher efficiencies than current generation of supercritical plants. This increased efficiency is expected to be achieved principally through the use of ultrasupercritical steam conditions (USC). The project goal initially was to assess/develop materials technology that will enable achieving turbine throttle steam conditions of 760 C (1400 F)/35 MPa (5000 psi), although this goal for the main steam temperature had to be revised down to 732 C (1350 F), based on a preliminary assessment of material capabilities. The project is intended to build further upon the alloy development and evaluation programs that have been carried out in Europe and Japan. Those programs have identified ferritic steels capable of meeting the strength requirements of USC plants up to approximately 620 C (1150 F) and nickel-based alloys suitable up to 700 C (1300 F). In this project, the maximum temperature capabilities of these and other available high-temperature alloys are being assessed to provide a basis for materials selection and application under a range of conditions prevailing in the boiler. This report provides a quarterly status report for the period of July 1 to September 30, 2004.

  3. BOILER MATERIALS FOR ULTRASUPERCRITICAL COAL POWER PLANTS

    Energy Technology Data Exchange (ETDEWEB)

    R. Viswanathan; K. Coleman; J. Shingledecker; J. Sarver; G. Stanko; M. Borden; W. Mohn; S. Goodstine; I. Perrin

    2004-10-30

    The U.S. Department of Energy (DOE) and the Ohio Coal Development Office (OCDO) have recently initiated a project aimed at identifying, evaluating, and qualifying the materials needed for the construction of the critical components of coal-fired boilers capable of operating at much higher efficiencies than current generation of supercritical plants. This increased efficiency is expected to be achieved principally through the use of ultrasupercritical steam conditions (USC). The project goal initially was to assess/develop materials technology that will enable achieving turbine throttle steam conditions of 760 C (1400 F)/35 MPa (5000 psi), although this goal for the main steam temperature had to be revised down to 732 C (1350 F), based on a preliminary assessment of material capabilities. The project is intended to build further upon the alloy development and evaluation programs that have been carried out in Europe and Japan. Those programs have identified ferritic steels capable of meeting the strength requirements of USC plants up to approximately 620 C (1150 F) and nickel-based alloys suitable up to 700 C (1300 F). In this project, the maximum temperature capabilities of these and other available high-temperature alloys are being assessed to provide a basis for materials selection and application under a range of conditions prevailing in the boiler. This report provides a quarterly status report for the period of April to June 30, 2004.

  4. BOILER MATERIALS FOR ULTRASUPERCRITICAL COAL POWER PLANTS

    Energy Technology Data Exchange (ETDEWEB)

    R. Viswanathan; K. Coleman; J. Shingledecker; J. Sarver; G. Stanko; W. Mohn; M. Borden; S. Goodstine; I. Perrin

    2004-07-30

    The U.S. Department of Energy (DOE) and the Ohio Coal Development Office (OCDO) have recently initiated a project aimed at identifying, evaluating, and qualifying the materials needed for the construction of the critical components of coal-fired boilers capable of operating at much higher efficiencies than current generation of supercritical plants. This increased efficiency is expected to be achieved principally through the use of ultrasupercritical steam conditions (USC). The project goal initially was to assess/develop materials technology that will enable achieving turbine throttle steam conditions of 760 C (1400 F)/35 MPa (5000 psi), although this goal for the main steam temperature had to be revised down to 732 C (1350 F), based on a preliminary assessment of material capabilities. The project is intended to build further upon the alloy development and evaluation programs that have been carried out in Europe and Japan. Those programs have identified ferritic steels capable of meeting the strength requirements of USC plants up to approximately 620 C (1150 F) and nickel-based alloys suitable up to 700 C (1300 F). In this project, the maximum temperature capabilities of these and other available high-temperature alloys are being assessed to provide a basis for materials selection and application under a range of conditions prevailing in the boiler. This report provides a quarterly status report for the period of April to June 30, 2004.

  5. BOILER MATERIALS FOR ULTRASUPERCRITICAL COAL POWER PLANTS

    Energy Technology Data Exchange (ETDEWEB)

    R. Viswanathan; K. Coleman; J. Shingledecker; J. Sarver; G. Stanko; M. Borden; W. Mohn; S. Goodstine; I. Perrin

    2005-01-31

    The U.S. Department of Energy (DOE) and the Ohio Coal Development Office (OCDO) have recently initiated a project aimed at identifying, evaluating, and qualifying the materials needed for the construction of the critical components of coal-fired boilers capable of operating at much higher efficiencies than current generation of supercritical plants. This increased efficiency is expected to be achieved principally through the use of ultrasupercritical steam conditions (USC). The project goal initially was to assess/develop materials technology that will enable achieving turbine throttle steam conditions of 760 C (1400 F)/35 MPa (5000 psi), although this goal for the main steam temperature had to be revised down to 732 C (1350 F), based on a preliminary assessment of material capabilities. The project is intended to build further upon the alloy development and evaluation programs that have been carried out in Europe and Japan. Those programs have identified ferritic steels capable of meeting the strength requirements of USC plants up to approximately 620 C (1150 F) and nickel-based alloys suitable up to 700 C (1300 F). In this project, the maximum temperature capabilities of these and other available high-temperature alloys are being assessed to provide a basis for materials selection and application under a range of conditions prevailing in the boiler. This report provides a quarterly status report for the period of July 1 to September 30, 2004.

  6. 'Boilers' along the southeast coast of Bermuda

    Science.gov (United States)

    2002-01-01

    Along the south shore of Bermuda, waves break continuously along algal/vermetid reefs (composed of algae and molluscs, not coral), forming 'boilers.' Boilers are named because the continuous breaking of waves makes it look as if the sea is boiling. This photograph taken from the International Space Station shows the eastern half of the main islands of Bermuda. Land use is about 6 percent cropland, 55 percent developed and 34 percent rural. Reflective white-colored areas are buildings and other developments surrounded by green areas of vegetation. St. David's Island is also home to the airport, with runways built out into Castle Harbour. Hurricane Erin passed northeast of Bermuda early on September 10 with 115 mile-per-hour winds (a Category 3 storm on the Saffir-Simpson Scale), but causing very minimal damage. Astronauts aboard Space Station Alpha photographed the area on September 14, 2001. By then, the skies had cleared and Erin had become an extratropical low near Newfoundland. Image ISS003-E-5735, was provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth.

  7. Steam generator tube failures

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-04-01

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

  8. Steam generator tube failures

    International Nuclear Information System (INIS)

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

  9. Steam generator tube rupture test conducted with Westinghouse MB-2 facility

    International Nuclear Information System (INIS)

    A response of a faulted steam generator to a tube rupture accident was simulated in the Westinghouse Model Boiler No. 2 test facility and data for primary liquid migration were obtained. Test data of collapsed liquid level were analyzed to find test consistency. Overall heat balance was evaluated. Then, carryover of the primary liquid to the steamline was estimated to be less than 0.4%

  10. Achieving reliable operation of a PSG-5000 delivery-water heater's tube system

    Science.gov (United States)

    Vasilenko, G. V.; Meshcheryakov, I. M.

    2010-01-01

    We analyze factors due to which damage occurred in the first period of operation in the 12Kh18N1 austenitic-steel tube system of the delivery-water heater used as part of a T-180/210-130 turbine unit operating in a couple with a high-pressure drum boiler. Technical solutions undertaken for achieving reliable operation of the heater are considered.

  11. Special requirements for pipe and tubing for nuclear and other special applications

    International Nuclear Information System (INIS)

    The specification provides special requirements for three classes of pipe and tubing corresponding to class 1, 2, and 3 in Section III, Division I of the ASME Boiler and Pressure Vessel Code. Mandatory requirements cover test specimen location for quenched and tempered materials, heat treatment, welding, elimination of surface defects, certification and identification, quality assurance, and time of nondestructive examination. Special requirements that may apply include eddy current examination, magnetic particle examination, liquid penetrant examination, radiographic examination, and ultrasonic examination

  12. SYSTEM FOR DETECTION AND CONTROL OF DEPOSITION IN KRAFT CHEMICAL RECOVERY BOILERS AND MONITORING GLASS FURNACES

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Peter Ariessohn

    2003-04-15

    Combustion Specialists, Inc. has just completed a project designed to develop the capability to monitor and control the formation of deposits on the outside of boiler tubes inside an operating kraft recovery furnace. This project, which was carried out in the period from April 1, 2001 to January 31, 2003, was funded by the Department of Energy's Inventions and Innovations program. The primary objectives of the project included the development and demonstration of the ability to produce clear images of deposits throughout the convective sections of operating recovery boilers using newly developed infrared imaging technology, to demonstrate the automated detection and quantification of these deposits using custom designed image processing software developed as part of the project, and to demonstrate the feasibility of all technical elements required for a commercial ''smart'' sootblowing control system based on direct feedback from automated imaging of deposits in real-time. All of the individual tasks have been completed and all objectives have been substantially achieved. Imaging of deposits throughout the convective sections of several recovery boilers has been demonstrated, a design for a combined sootblower/deposit inspection probe has been developed and a detailed heat transfer analysis carried out to demonstrate the feasibility of this design, an improved infrared imager which can be sufficiently miniaturized for this application has been identified, automated deposit detection software has been developed and demonstrated, a detailed design for all the necessary communications and control interfaces has been developed, and a test has been carried out in a glass furnace to demonstrate the applicability of the infrared imaging sensor in that environment. The project was completed on time and within the initial budget. A commercial partner has been identified and further federal funding will be sought to support a project to develop a

  13. Can the lifetime of the superheater tubes be predicted according to the fuel analyses? Assessment from field and laboratory data

    Energy Technology Data Exchange (ETDEWEB)

    Salmenoja, K. [Kvaerner Pulping Oy, Tampere (Finland)

    1998-12-31

    Lifetime of the superheaters in different power boilers is more or less still a mystery. This is especially true in firing biomass based fuels (biofuels), such as bark, forest residues, and straw. Due to the unhomogeneous nature of the biofuels, the lifetime of the superheaters may vary from case to case. Sometimes the lifetime is significantly shorter than originally expected, sometimes no corrosion even in the hottest tubes is observed. This is one of the main reasons why the boiler operators often demand for a better predictability on the corrosion resistance of the materials to avoid unscheduled shutdowns. (orig.) 9 refs.

  14. Pyrotechnic Tubing Connector

    Science.gov (United States)

    Graves, Thomas J.; Yang, Robert A.

    1988-01-01

    Tool forms mechanical seal at joint without levers or hydraulic apparatus. Proposed tool intended for use in outer space used on Earth by heavily garbed workers to join tubing in difficult environments. Called Pyrotool, used with Lokring (or equivalent) fittings. Piston slides in cylinder when pushed by gas from detonating pyrotechnic charge. Impulse of piston compresses fittings, sealing around butting ends of tubes.

  15. Welding Tubes In Place

    Science.gov (United States)

    Meredith, R.

    1984-01-01

    Special welding equipment joins metal tubes that carry pressurized cyrogenic fluids. Equipment small enough to be used in confined spaces in which such tubes often mounted. Welded joints lighter in weight and more leak-proof than joints made with mechanical fittings.

  16. Theoretical development of a thermal model for the reheater of a power plant boiler

    International Nuclear Information System (INIS)

    A three-dimensional numerical model for simulating flow and heat transfer in the reheater of a boiler is presented. The aim is to describe, as well as possible, the geometry of the reheater and to be able to perform different mass flows of steam along each of the tube serpentines. The model thus makes it possible to calculate the temperature of the tube surfaces along the reheater. The porosity concept is employed, along with empirical correlations for the convective heat transfer coefficient and the radiation heat transfer coefficients. The radiation equations consider most of the radiative effects of the gas: ash content, triatomic gases, type of fuel and temperatures, tube layout and distances and temperatures of other radiative surfaces. The model is proposed with a view to using the measured values of velocities, temperatures and gas composition in the reheater as boundary conditions. The equations are solved using a general purpose computational fluid dynamics (CFD) code in conjunction with specific calculations for the source terms

  17. Categorising YouTube

    DEFF Research Database (Denmark)

    Simonsen, Thomas Mosebo

    2011-01-01

    This article provides a genre analytical approach to creating a typology of the User Generated Content (UGC) of YouTube. The article investigates the construction of navigation processes on the YouTube website. It suggests a pragmatic genre approach that is expanded through a focus on YouTube’s...... technological affordances. Through an analysis of the different pragmatic contexts of YouTube, it is argued that a taxonomic understanding of YouTube must be analysed in regards to the vacillation of a user-driven bottom-up folksonomy and a hierarchical browsing system that emphasises a culture of competition...... and which favours the already popular content of YouTube. With this taxonomic approach, the UGC videos are registered and analysed in terms of empirically based observations. The article identifies various UGC categories and their principal characteristics. Furthermore, general tendencies of the UGC...

  18. 46 CFR 71.15-1 - Standards in inspection of hulls, boilers, and machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Standards in inspection of hulls, boilers, and machinery..., boilers, and machinery. In the inspection of hulls, boilers, and machinery of vessels, the standards... and inspection of hulls, boilers, and machinery, and the certificate of classification...

  19. 46 CFR 189.15-1 - Standards in inspection of hulls, boilers, and machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Standards in inspection of hulls, boilers, and machinery... inspection of hulls, boilers, and machinery. In the inspection of hulls, boilers, and machinery of vessels... chapter, respecting material and construction of hulls, boilers, and machinery, and certificate...

  20. 46 CFR 91.15-1 - Standards in inspection of hulls, boilers, and machinery.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Standards in inspection of hulls, boilers, and machinery... hulls, boilers, and machinery. In the inspection of hulls, boilers, and machinery of vessels, the..., respecting material and inspection of hulls, boilers, and machinery, and the certificate of...

  1. 49 CFR 230.20 - Alteration and repair report for steam locomotive boilers.

    Science.gov (United States)

    2010-10-01

    ... boilers. (a) Alterations. When an alteration is made to a steam locomotive boiler, the steam locomotive... steam locomotive boiler, the steam locomotive owner and/or operator shall file with the FRA Regional... the boiler. Whenever welded or riveted repairs are performed on stayed portions of a steam...

  2. Wood Pellet-Fired Biomass Boiler Project at the Ketchikan Federal Building

    Energy Technology Data Exchange (ETDEWEB)

    Tomberlin, G.

    2014-06-01

    Biomass boiler systems have existed for many years, but the technology has advanced in recent decades and can now provide automated and efficient operation for a relatively modest investment. Key advances in system monitoring and control allow for lower operating costs, since the control systems run all aspects of the boiler, including feed, load reduction and even tube cleaning. These advances have made such systems economical on a small scale in situations where inexpensive fuels like natural gas are not available. This creates an opportunity for building operators in remote, cold-climate locations to reduce the use of expensive fuels for heating buildings. GSA Region 10 installed the system at the federal building in Ketchikan, Alaska and submitted the project to the Green Proving Ground (GPG) program. GSA's GPG program contracted with the National Renewable Energy Laboratory (NREL) to assess the installation and the technology. The system serves as a demonstration to assess actual system efficiencies, as well as operating characteristics and financial benefits. In addition to installation and operational issues, the project team/researchers examined other issues, including fuel transportation costs, building energy savings, and overall economics.

  3. 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.

  4. Evaluation of conditions of SNCR in small boilers

    International Nuclear Information System (INIS)

    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

  5. Modeling operation mode of pellet boilers for residential heating

    International Nuclear Information System (INIS)

    In recent years the consumption of wood pellets as energy source for residential heating lias increased, not only as fuel for stoves, but also for small-scale residential boilers that, produce hot water used for both space heating and domestic hot water. Reduction of fuel consumption and pollutant emissions (CO, dust., HC) is an obvious target of wood pellet boiler manufacturers, however they are also quite interested in producing low- maintenance appliances. The need of frequent maintenance turns in higher operating costs and inconvenience for the user, and in lower boiler efficiency and higher emissions also. The aim of this paper is to present a theoretical model able to simulate the dynamic behavior of a pellet boiler. The model takes into account many features of real pellet boilers. Furthermore, with this model, it is possible to pay more attention to the influence of the boiler control strategy. Control strategy evaluation is based not only on pellet consumption and on total emissions, but also on critical operating conditions such as start-up and stop or prolonged operation at substantially reduced power level. Results are obtained for a residential heating system based on a wood pellet boiler coupled with a thermal energy storage. Results obtained so far show a weak dependence of performance in terms of fuel consumption and total emissions on control strategy, however some control strategies present some critical issues regarding maintenance frequency

  6. MSWI Boiler Ashes: Production and Quality Through the Horizontal Section of a Boiler

    DEFF Research Database (Denmark)

    Allegrini, Elisa; Boldrin, Alessio; Astrup, Thomas Fruergaard

    SUMMARY: the central role of waste-to-energy (WtE) plants in Denmark asks for a deep knowledge of all different residues produced by these facilities. The main objective of solid residues characterization is the optimization of their management system. In this study we present the results of the...... first phase of a wider study about the solid residues produced at the heat recovery system (boiler) of a waste incineration plant. The characterization was carried out not on the total output of the boiler but on the different solid residues produced at ten different horizontal sections. The aim was to...... characterize the different streams in order to identify differences that can justify potentially different utilization/disposal options. First results showed differences between sections in terms of chemical composition, leaching behavior and content of dioxins, but additional results are needed to cope with...

  7. Differences in the composition of organic impurities in ground and surface waters. Consequences for the preparation of boiler feed water

    International Nuclear Information System (INIS)

    It is generally accepted that current limits for total organic carbon (TOC) in the pharmaceutical industry (500 ppb) and semiconductor industry (10-25 ppb) should be regarded as precautionary measures and do not necessarily reflect true scientific evidence. For the power industry the situation is different. Here, recommended TOC-limits for boiler feed waters (in 1999: VGB: 200 ppb; EPRI: 100 ppb) are based on scientific and empirical data. The oxidation of, say, 50 ppb TOC to carbon dioxide in the water/steam cycle will increase steam condensate conductivity by 0.48 μS/cm (values may depend on literature source, here [1]), a value which is not acceptable as it desensitizes the detection of leaks in cooling water heat exchangers. Apart from this indirect effect of TOC there is also evidence for direct negative effects of TOC on steel materials. Even small amounts of organic acids, which are produced as intermediates in the TOC oxidation process, may locally lower the pH down to levels [2] where erosion corrosion of boiler tubes can take place. It was also found that carbon is enriched in stress corrosion cracks of turbine materials [3]. The present paper will discuss the ''TOC-issue'' in boiler feed water preparation. Most of the results can be applied also to other industries, e.g. semiconductor, chemical or pharmaceutical. (authors)

  8. Comparative study of emissions in a generator of vapor when natural gas and boiler diesel is used

    International Nuclear Information System (INIS)

    In a fire-tube industrial dual boiler of 30 BHP that uses natural gas of Guajira and diesel, one measurements and calculates the emissions factor of atmospherics pollutions such carbon dioxide and monoxide, nitrogen oxides, sulfur oxides, hydrocarbon totals and methanics and particulate matter (CO2, CO, NOx, SOx, HC, CH4 and MP respectively). The results were obtained using air factors of 1.07, 1.16, 1.26, 1.34 and 1.45 and in a boiler is keeping constant the thermal heat input and ranging vapor pressure. Of the comparative analysis of emissions one concludes that the CO2, CO, SO2, CH4 and MP emissions are always greater for the diesel with respect to the natural gas. With respect to the HC and NO emissions, although they do not present a regular tendency between a fuel and another one, its behavior reveals that the air factor used in the process produces a significant effect in its emission and that the mechanisms of formation of these polluting can be related to the chemical composition of the fuel and to the variation of the air factor in the boiler

  9. Numerical analysis of flow instability in the water wall of a supercritical CFB boiler with annular furnace

    Science.gov (United States)

    Xie, Beibei; Yang, Dong; Xie, Haiyan; Nie, Xin; Liu, Wanyu

    2016-08-01

    In order to expand the study on flow instability of supercritical circulating fluidized bed (CFB) boiler, a new numerical computational model considering the heat storage of the tube wall metal was presented in this paper. The lumped parameter method was proposed for wall temperature calculation and the single channel model was adopted for the analysis of flow instability. Based on the time-domain method, a new numerical computational program suitable for the analysis of flow instability in the water wall of supercritical CFB boiler with annular furnace was established. To verify the code, calculation results were respectively compared with data of commercial software. According to the comparisons, the new code was proved to be reasonable and accurate for practical engineering application in analysis of flow instability. Based on the new program, the flow instability of supercritical CFB boiler with annular furnace was simulated by time-domain method. When 1.2 times heat load disturbance was applied on the loop, results showed that the inlet flow rate, outlet flow rate and wall temperature fluctuated with time eventually remained at constant values, suggesting that the hydrodynamic flow was stable. The results also showed that in the case of considering the heat storage, the flow in the water wall is easier to return to stable state than without considering heat storage.

  10. Theory and Practice of steel surface protection in boilers; Schutz der Stahloberflaechen von Dampferzeugern. Theorie und Praxis

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, J.P.; Daucik, K. [SV Produktion a.m.b.a., Skaerbaek, Fredericia (Denmark); Smitshuysen, E.F. [Faelleskemikerne, I/S Vestkraft, Esbjerg (Denmark)

    1999-10-01

    Protective magnetite steel surface layers developing in steam generators may be subject to aggressive attacks. However, even if general guidelines for the bulk water are met with respect to the water purity (acid conductivity) and conditioning chemicals, damage can occur. The reason may be the disregarding of interaction among material, design and chemistry. Different boiler water treatments are discussed in detail. The influence of pressure and pH on the stability of the protective layer is described. Experience on how solid alkaline conditioning combined with inadequate design can result in severe corrosion and boiler tube failures is outlined. It is also being described how simple modifications of the boiler design can resolve solid alkaline corrosion. (orig.) [Deutsch] Magnetit-Schutzschichten, die sich auf den Stahlflaechen von Dampferzeugern ausbilden, sind oftmals aggressiven Angriffen ausgesetzt. Daraus koennen sich Schaeden entwickeln, die nur durch optimales Speise- und Kesselwasser vermieden werden koennen. Doch selbst bei Einhaltung allgemeiner Richtlinien im Hinblick auf Wasserreinheit (Saeureleitfaehigkeit) und Alkalisierungsmittel koennen Schaeden auftreten, wenn bedeutende, sich gegenseitig beeinflussende Parameter, wie Werkstoffwahl, Auslegung und chemische Fahrweise, nicht ausreichend beachtet werden. Die unterschiedlichen Moeglichkeiten der Wasserkonditionierung werden detailliert eroertert. Druck und pH-Wert nehmen ebenfalls Einfluss auf die Stabilitaet der Schutzschicht. Die Autoren berichten ueber Faelle, in denen feste Alkalisierungsmittel in Kombination mit einer nicht geeigneten Kesselkonstruktion zu schwerwiegender Korrosion und Rohrschaeden gefuehrt haben. Weiterhin wird gezeigt, wie dank einfacher Veraenderungen am Dampferzeuger das durch feste Alkalisierungsmittel hervorgerufene Korrosionsproblem geloest werden kann. (orig.)

  11. BOILER MATERIALS FOR ULTRASUPERCRITICAL COAL POWER PLANTS

    Energy Technology Data Exchange (ETDEWEB)

    R. Viswanathan; K. Coleman

    2002-10-15

    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

  12. 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

  13. BOILER MATERIALS FOR ULTRASUPERCRITICAL COAL POWER PLANTS

    Energy Technology Data Exchange (ETDEWEB)

    R. Viswanathan

    2002-04-15

    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), and up to 5500 psi with emphasis upon 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 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

  14. COAL COMBUSTION EFFICIENCY IN CFB BOILER

    Institute of Scientific and Technical Information of China (English)

    Hairui Yang; Guangxi Yue

    2005-01-01

    The carbon content in the fly ash from most Chinese circulating fluidized bed (CFB) boilers is much higher than expected, thus directly influencing the combustion efficiency. In the present paper, carbon burnout was investigated both in field tests and laboratory experiments. The effect of coal property, operation condition, gas-solid mixing, char deactivation,residence time and cyclone performance are analyzed seriatim based on large amount of experimental results.A coal index is proposed to describe the coal rank, defined by the ratio of the volatile content to the coal heat value, is a useful parameter to analyze the char burnout. The carbon content in the fly ash depends on the coal rank strongly. CFB boilers burning anthracite, which has low coal index, usually have high carbon content in the fly ash. On the contrary, the CFB boilers burning brown coal, which has high coal index, normally have low carbon content.Poor gas-solid mixing in the furnace is another important reason of the higher carbon content in the fly ash. Increasing the velocity and rigidity of the secondary air could extend the penetration depth and induce more oxygen into the furnace center. Better gas solid mixing will decrease the lean oxygen core area and increase char combustion efficiency.The fine char particles could be divided into two groups according to their reactivity. One group is "fresh" char particles with high reactivity and certain amount of volatile content. The other group of char particles has experienced sufficient combustion time both in the furnace and in the cyclone, with nearly no volatile. These "old" chars in the fly ash will be deactivated during combustion of large coal particles and have very low carbon reactivity. The generated fine inert char particles by attrition of large coal particles could not easily burn out even with the fly ash recirculation. The fraction of large coal particles in coal feed should be reduced during fuel preparation process.The cyclone

  15. BOILER MATERIALS FOR ULTRASUPERCRITICAL COAL POWER PLANTS

    Energy Technology Data Exchange (ETDEWEB)

    R. Viswanathan; K. Coleman

    2002-07-15

    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

  16. Probe Measurements of Ash Deposit Formation Rate and Shedding in a Biomass Suspension-Fired boiler

    DEFF Research Database (Denmark)

    Shafique Bashir, Muhammad; Jensen, Peter Arendt; Frandsen, Flemming;

    The aim of this study was to investigate ash deposit formation rate, heat uptake reduction and deposit removal by using advanced online ash deposition and sootblowing probes in a 350 MWth suspension-fired boiler, utilizing wood and straw pellets as fuel. The influence of fuel type (straw share in...... wood), probe exposure time, probe surface temperature (500, 550 and 600 oC) and flue gas temperature (600 - 1050 oC) on ash deposit formation rate, heat uptake by the probe, the fly ash and deposit characteristics, and deposit removal have been investigated. The results indicated that increase in flue...... video recordings of all deposit probe experiments revealed that deposit shedding was primarily through debonding from the surface of the tubes in the superheater region. Chemical analysis of fly ashes indicated that during suspension-firing of straw and wood, the fly ashes were rich in Si, K, Ca and Cl...

  17. Improved soot blowing, based on needs, through measurement of the natural frequency of the heat transferring tubes; Foerbaettrad behovsstyrd sotning genom maetning av oeverfoerande tubernas egenfrekvens

    Energy Technology Data Exchange (ETDEWEB)

    Blom, Elisabet; Ivarsson, Christofer

    2007-11-15

    The aim of the project is to develop a method for detecting soot on the transferring tubes by measuring the Eigen frequency of the tubes as a function of the soot deposit growth. The project is a pilot study independent of boiler type and it is applicable to all boilers where soot deposit on transferring tubes is a repeating issue. The report is supposed to answer two major questions. Is it possible to make use of Eigen frequencies in order to trace soot deposit on transferring tubes? What governing parameters are related to the Eigen frequency of transferring tubes? By today, soot blowing is executed after recommendations from the manufacturer in terms of number of soot blowing per time unit. The fuel type as well as boiler type has great influence on the soot deposit growth. The objective of the project is to investigate whether the mechanical properties of the transferring tube can be used to detect soot deposit. The project is divided into a theoretical and a practical part. The theoretical part covers the design of the probe and the change of its mechanical properties when soot deposit is present. Practical experiments were then carried out in a laboratory were the probes mechanical properties with and without soot deposit were investigated. It was shown that the Eigen frequency of the probe decreased with an increased mass due to soot deposit. A test was also made in a boiler at SAKAB but difficulties in attaching the probe to the inspection hatch. The results varied and the interpretation of the results become difficult. However, it was obvious that the mechanical properties of the probe changed with the amount of soot deposit. It was concluded that detection of soot deposit by studying the mechanical properties of the transferring tubes is possible. Yet, using a probe is no optimal solution, instead measurements should be done directly on the heat transferring tubes. In addition, a strategy for controlling the soot deposit has to be developed

  18. The nondestructive testing of tubes and pipes for nuclear application

    International Nuclear Information System (INIS)

    The directive of the Reactor Safety Commission demands for all materials which are provided for the pressure bearing enclosure of the refrigerant a nondestructive testing with sufficient sensibility. The specification 3201.1 for nuclear application as well as company-internal rules of important manufacturers regulate the requirements derived from the above direction for the NDT of tubes and pipes. For an objective and reproducible testing, equipments with defined characteristics are employed, based on internal specifications, testing equipments are fabricated and then checked with a special computerized test system. Moreover probes are controlled with regard to their acoustic and electric properties. The NDT of heat exchanger tubes and of pipes is given here as an example: Heat exchanger tubes: The tests include the inspection of longitudinal and transverse defects, wall thickness, dimension and tightness. In connection with the NDT, defect catalogues are set up. By this means the chosen test sensitivity is verified, and so the high quality of the tubes is assured. Specially developed eddy-current methods prove that such tested tubes are free of corrosion-causing phases. Pipes: The pipes are tested for longitudinal and transverse defects, for laminations and for wall thickness. To fulfil the demand for an objective and reproducible testing, there was developed and installed an automatic, computer-controlled ultrasonic equipment with 40 probes. Development trends: For the NDT of heat exchanger and boiler tubes an electrodynamic excited ultrasonic test system is evolved which is also able to test curved and installed tubes. The sophisticated testing technology is completed by a qualified education and training of NDT personnel. (orig.)

  19. Extending EMMS-based models to CFB boiler applications

    Institute of Scientific and Technical Information of China (English)

    Bona Lu; Nan Zhang; Wei Wang; Jinghai Li

    2012-01-01

    Recently,EMMS-based models are being widely applied in simulations of high-throughput circulating fluidized beds (CFBs) with fine particles.Its use for low flux systems,such as CFB boiler (CFBB),still remains unexplored.In this work,it has been found that the original definition of cluster diameter in EMMS model is unsuitable for simulations of the CFB boiler with low solids flux.To remedy this,we propose a new model of cluster diameter.The EMMS-based drag model (EMMS/matrix model) with this revised cluster definition is validated through the computational fluid dynamics (CFD) simulation of a CFB boiler.

  20. Model-based Control of a Bottom Fired Marine Boiler

    DEFF Research Database (Denmark)

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

    This paper focuses on applying model based MIMO control to minimize variations in water level for a specific boiler type. A first principles model is put up. The model is linearized and an LQG controller is designed. Furthermore the benefit of using a steam °ow measurement is compared to a strategy...... relying on estimates of the disturbance. Preliminary tests at the boiler system show that the designed controller is able to control the boiler process. Furthermore it can be concluded that relying on estimates of the steam flow in the control strategy does not decrease the controller performance...