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Sample records for boiler tube fouling

  1. Surface chemistry interventions to control boiler tube fouling

    Energy Technology Data Exchange (ETDEWEB)

    Turner, C.W.; Guzonas, D.A.; Klimas, S.J

    2000-06-01

    The adsorption of ammonia, morpholine, ethanolamine, and dimethylamine onto the surfaces of colloidal magnetite and hematite was measured at 25{sup o}C. 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.

  2. Surface chemistry interventions to control boiler tube fouling

    International Nuclear Information System (INIS)

    Turner, C.W.; Guzonas, D.A.; Klimas, S.J.

    2000-06-01

    The adsorption of ammonia, morpholine, ethanolamine, and dimethylamine onto the surfaces of colloidal magnetite and hematite was measured at 25 o C. 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

  3. Failure analysis of boiler tube

    International Nuclear Information System (INIS)

    Mehmood, K.; Siddiqui, A.R.

    2007-01-01

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

  4. Boiler tube failure prevention in fossil fired boilers

    International Nuclear Information System (INIS)

    Townsend, R.D.

    1993-01-01

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

  5. 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.

  6. 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

  7. 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.

  8. Residual strain distribution in bent composite boiler tubes

    International Nuclear Information System (INIS)

    Tang Fei; Hubbard, Camden R.; Sarma, Gorti; Keiser, James

    2006-01-01

    Kraft recovery boilers are typically constructed of carbon steel boiler tubes clad with a corrosion resistant layer, and these composite tubes are bent and welded together to form air port panels which enable the combustion air to enter the boiler. In this paper, the through-thickness residual strain in the carbon steel layer of non-heat-treated and heat-treated composite bent tubes were measured by neutron diffraction techniques and modeled by finite element modeling. The results can be used to optimize material selection and manufacturing processes to prevent stress corrosion and corrosion fatigue cracking in the boiler tubes

  9. 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...

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

    International Nuclear Information System (INIS)

    Ishiyama, Toru; Kawasaki, Ichio; Miura, Hirohito

    2014-01-01

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

  11. Influence of Sorbent Characteristics on Fouling and Deposition in Circulating Fluid Bed Boilers Firing High Sulfur Indian Lignite

    Directory of Open Access Journals (Sweden)

    Selvakumaran Palaniswamy

    2013-01-01

    Full Text Available 125 MWe circulating fluidized bed combustion (CFBC boiler experienced severe fouling in backpass of the boiler leading to obstruction of gas flow passage, while using high sulfur lignite with sorbent, calcium carbonate, to capture sulfur dioxide. Optical microscopy of the hard deposits showed mainly anhydrite (CaSO4 and absence of intermediate phases such as calcium oxide or presence of sulfate rims on decarbonated limestone. It is hypothesized that loose unreacted calcium oxides that settle on tubes are subjected to recarbonation and further extended sulfation resulting in hard deposits. Foul probe tests were conducted in selected locations of backpass for five different compositions of lignite, with varied high sulfur and ash contents supplied from the mines along with necessary rates of sorbent limestone to control SO2, and the deposits build-up rate was determined. The deposit build-up was found increasing, with increase in ash content of lignite, sorbent addition, and percentage of fines in limestone. Remedial measures and field modifications to dislodge deposits on heat transfer surfaces, to handle the deposits in ash conveying system, and to control sorbent fines from the milling circuit are explained.

  12. CONCENTRIC TUBE-FOULING RIG FOR INVESTIGATION OF FOULING DEPOSIT FORMATION FROM PASTEURISER OF VISCOUS FOOD LIQUID

    Directory of Open Access Journals (Sweden)

    N. I. KHALID

    2013-02-01

    Full Text Available This paper reports the work on developing concentric tube-fouling rig, a new fouling deposit monitoring device. This device can detect and quantify the level of fouling deposit formation. It can also functioning as sampler for fouling deposit study, which can be attached at any food processing equipment. The design is initiated with conceptual design. The rig is designed with inner diameter of 7 cm and with tube length of 37 cm. A spiral insert with 34.5 cm length and with 5.4 cm diameter is fitted inside the tube to ensure the fluid flows around the tube. In this work, the rig is attached to the lab-scale concentric tube-pasteurizer to test its effectiveness and to collect a fouling sample after pasteurization of pink guava puree. Temperature changes are recorded during the pasteurization and the data is used to plot the heat transfer profile. Thickness of the fouling deposit is also measured. The trends for thickness, heat resistance profile and heat transfer profile for concentric tube-fouling rig matched the trends obtained from lab-scale concentric tube-pasteurizer very well. The findings from this work have shown a good potential of this rig however there is a limitation with spiral insert, which is discussed in this paper.

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

    Directory of Open Access Journals (Sweden)

    Shi Yuanhao

    2015-01-01

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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  15. Creep analysis of boiler tubes by fem | Taye | Zede Journal

    African Journals Online (AJOL)

    In this paper an analysis is developed for the determination of creep deformation of an axisymmetric boiler tubes subjected to axisymmetric loads. The stresses and the permanent strains at a particular time and at the steady state condition, resulting from loading of the tube under constant internal pressure and elevated ...

  16. Modelling and simulating fire tube boiler performance

    DEFF Research Database (Denmark)

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

    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....

  17. Investigation of Turbulators for Fire Tube Boilers Using Exergy Analysis

    OpenAIRE

    AYHAN, Betül

    2001-01-01

    In this paper, an experimental study of five different types of ``turbulator" inserts for fire tube boilers is presented. The experimental setup was constructed in the Department of Mechanical Engineering Laboratory of Karadeniz Technical University. It was tested to evaluate the boiler efficiency according to TS 4040 standard, and to evaluate the second law efficiency of thermodynamics for the cases with and without inserts under the same operating conditions. Four new typ...

  18. Failure analysis of the boiler water-wall tube

    Directory of Open Access Journals (Sweden)

    S.W. Liu

    2017-10-01

    Full Text Available Failure analysis of the boiler water-wall tube is presented in this work. In order to examine the causes of failure, various techniques including visual inspection, chemical analysis, optical microscopy, scanning electron microscopy and energy dispersive spectroscopy were carried out. Tube wall thickness measurements were performed on the ruptured tube. The fire-facing side of the tube was observed to have experienced significant wall thinning. The composition of the matrix material of the tube meets the requirements of the relevant standards. Microscopic examinations showed that the spheroidization of pearlite is not very obvious. The failure mechanism is identified as a result of the significant localized wall thinning of the boiler water-wall tube due to oxidation.

  19. Hybrid Intelligent Warning System for Boiler tube Leak Trips

    Directory of Open Access Journals (Sweden)

    Singh Deshvin

    2017-01-01

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

  20. Monitoring and prediction of fouling in coal-fired utility boilers using neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Teruel, E.; Cortes, C.; Diez, L.I.; Arauzo, I. [University of Zaragoza, Zaragoza (Spain)

    2005-09-01

    This paper describes a systematic approach to predict ash deposits in coal-fired boilers by means of artificial neural networks. The approach is of a 'grey box' nature, decomposing the problem into logical parts, and avoiding the use of sophisticated data. Although it is relative to the specific fuel and equipment, the prediction is very detailed and can be used on-line; it accounts not only for the deposition rate, but also for short-term cleaning occurrences, thus simulating a complex and chaotic time-evolution. The model is developed with the aid of a case-study, that of the fouling of a furnace, as detected by heat flux meters. Provided that an adequate amount of heat transfer measurements can be gathered, the procedure can be used to simulate the evolution of boiler heat absorption under realistic conditions of deposition. Applications include obviously new possibilities for automatic control of the equipment, as well as the optimization of operating set points to maximize thermal efficiency, such as the sequence and operation of on-load cleaning devices. It is thought that the method developed would be applicable to other instances of fouling or equipment degradation exhibiting similar behavior, specially with respect to on-line corrective measures.

  1. Tube micro-fouling, boiling and steam pressure after chemical cleaning

    International Nuclear Information System (INIS)

    Hu, M.H.

    1998-01-01

    This paper presents steam pressure trends after chemical cleaning of steam generator tubes at four plants. The paper also presents tube fouling factor that serves as an objective parameter to assess tubing boiling conditions for understanding the steam pressure trend. Available water chemistry data helps substantiate the concept of tube micro-fouling, its effect on tubing boiling, and its impact on steam pressure. All four plants experienced a first mode of decreasing steam pressure in the post-cleaning operation. After 3 to 4 months of operation, the decreasing trend stopped for three plants and then restored to a pre-cleaning value or better. The fourth plant is soil in decreasing trend after 12 months of operation. Dissolved chemicals, such as silica, titanium can precipitate on tube surface. The precipitate micro-fouling can deactivate or eliminate boiling nucleation sites. Therefore, the first phase of the post-cleaning operation suffered a decrease in steam pressure or an increase in fouling factor. It appears that micro fouling by magnetite deposit can activate or create more bubble nucleation sites. Therefore, the magnetite deposit micro-fouling results in a decrease in fouling factor, and a recovery in steam pressure. Fully understanding the boiling characteristics of the tubing at brand new, fouled and cleaned conditions requires further study of tubing surface conditions. Such study should include boiling heat transfer tests and scanning electronic microscope examination. (author)

  2. Modelling and simulating fire tube boiler performance

    DEFF Research Database (Denmark)

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

    2003-01-01

    : 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...

  3. 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...

  4. 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

  5. Study on Acoustic Catheter of Boiler Tube Leakage Monitoring Systems

    Science.gov (United States)

    Lv, Yongxing; Feng, Qiang

    Boiler tube leakage is the major reason of affecting the safe operation of the unit now, there are 3 methods of the "four tube" leakage detection: Traditional method, filtering method and acoustic spectrum analysis, acoustic spectrum analysis is the common method, but this method have low sensitivity and the sensor damage easily. Therewith, designed the special acoustic catheter with acoustic resonance cavity type, proved by experiments, the acoustic catheter with acoustic resonance cavity type can enhance leakage sound, can accurately extract leakage signals, has high sensitivity, and can avoid the effect of sensor by fire and hot-gas when the furnace is in positive pressure situation, reduce the installation and maintenance costs of the boiler tube leakage monitor system.

  6. Thermal design of horizontal tube boilers: numerical and experimental investigation

    International Nuclear Information System (INIS)

    Roser, Robert

    1999-01-01

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

  7. New insights into controlling tube-bundle fouling using alternative amines

    International Nuclear Information System (INIS)

    Turner, C.W.; Klimas, S.J.; Guzonas, D.A.; Frattini, P.L.; Fruzzetti, K.

    2002-01-01

    A volatile amine is added to the secondary heat-transport system of a nuclear power plant to reduce the rate of corrosion and corrosion product transport in the feedwater and to protect steam generator (SG) crevices and materials exposed to steam condensate. Volatility and base strength of the amine at the SG operating temperature are two important considerations when choosing the optimum amine (or mixture of amines) for corrosion control in the steam cycle. Atomic Energy of Canada Limited (AECL) and Electric Power Research Institute (EPRI) have been collaborating in an extensive investigation of the effectiveness of amines at controlling the rate of tube-bundle fouling under SG operating conditions. Tests have been performed using a radiotracing technique in a high-temperature fouling loop facility at Chalk River Laboratories operated by AECL. This investigation has provided new insights into the role played by the amine in determining the rate of tube-bundle fouling in the SG. These insights are being used by AECL and EPRI to develop criteria for the selection of an amine that has optimum properties for both corrosion control and deposit control in the secondary heat transport system. The investigation has found that the rate of tube-bundle fouling is strongly dependent upon the surface chemistry of the corrosion products. For example, the fouling rates of fully oxidized iron oxides, such as hematite and lepidocrocite, are at least an order of magnitude greater than the fouling rate of magnetite under identical operating conditions. The difference is related to the sign of the surface charge on the corrosion products at temperature. The choice of amine for pH-control also influences the fouling rate. This was originally thought to be a surface-charge effect as well, but recent tests have suggested that it is related to the role that the amine plays in governing the rate of deposit consolidation on the heat-transfer surface. Amines that promote a high rate of

  8. A study on the leak monitoring of boiler tube in power plants

    International Nuclear Information System (INIS)

    Lee, Sang Guk

    2002-01-01

    Main equipment of thermal power plant, such as boiler and turbine, are designed and manufactured by domestic techniques. But the special equipments monitoring the operation status of these main facilities are still dependent upon foreign technology. Therefore, so as to develop boiler tube leak detection system, we performed studying on manufacturing, installation in site, Acoustic Emission (AE) signal analysis and discrimination etc. As 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 plant facilities

  9. Use of genetic algorithm to identify thermophysical properties of deposited fouling in heat exchanger tubes

    International Nuclear Information System (INIS)

    Adili, Ali; Ben Salah, Mohieddine; Kerkeni, Chekib; Ben Nasrallah, Sassi

    2009-01-01

    At high temperature, the circulation of fluid in heat exchangers provides a tendency for fouling accumulation to take place on the internal surface of tubes. This paper shows an experimental process of thermophysical properties estimation of the fouling deposited on internal surface of a heat exchanger tube using genetic algorithms (GAs). The genetic algorithm is used to minimize an objective function containing calculated and measured temperatures. The experimental bench using a photothermal method with a finite width pulse heat excitation is used and the estimated parameters are obtained with high accuracy

  10. The Thermal Hydraulics of Tube Support Fouling in Nuclear Steam Generators

    International Nuclear Information System (INIS)

    Rummens, Helena E.C.; Rogers, J.T.; Turner, C.W.

    2004-01-01

    It is hypothesized that the thermal-hydraulic environment plays a role in the fouling of tube supports in nuclear steam generators. Experiments were performed to simulate the thermal-hydraulic environment near various designs of supports. Pressure loss, local velocity, turbulence intensity, and local void fraction were measured to characterize the effect of the support. Fouling mechanisms specific to supports were inferred from these experimental data and from actual steam generator inspection results. An analytical model was developed to predict the rate of particulate deposition on the supports, to better understand the complex processes involved.This paper presents the following set of tools for assessing the fouling propensity of a given support design: (1) proposed fouling mechanisms, (2) criteria for support fouling propensity, (3) correlation of fouling with parameters such as mass flux and quality, (4) descriptions of experimental tools such as flow visualization and measurement of pressure-loss profiles, and (5) analytical tools.An important conclusion from this and our previous work is that the fouling propensity is greater with broached support plates, both trefoil and quatrefoil, than with lattice bar supports and formed bar supports, in which significant cross flows occur

  11. Heat exchanger fouling: Prediction, measurement, and mitigation

    Science.gov (United States)

    The US Department of Energy (DOE), Office of Industrial Programs (OIP) sponsors the development of innovative heat exchange systems. Fouling is a major and persistent cost associated with most industrial heat exchangers and nationally wastes an estimated 2.9 Quads per year. To predict and control fouling, three OIP projects are currently exploring heat exchanger fouling in specific industrial applications. A fouling probe has been developed to determine empirically the fouling potential of an industrial gas stream and to derive the fouling thermal resistance. The probe is a hollow metal cylinder capable of measuring the average heat flux along the length of the tube. The local heat flux is also measured by a heat flux meter embedded in the probe wall. The fouling probe has been successfully tested in the laboratory at flue gas temperatures up to 2200 F and a local heat flux up to 41,000 BTU/hr sq ft. The probe has been field tested at a coal-fired boiler plant. Future tests at a municipal waste incinerator are planned. Two other projects study enhanced heat exchanger tubes, specifically the effect of enhanced surface geometries on the tube bundle performance. Both projects include fouling in a liquid heat transfer fluid. Identifying and quantifying the factors affecting fouling in these enhanced heat transfer tubes will lead to techniques to mitigate fouling.

  12. Design of shell-and-tube heat exchangers when the fouling depends on local temperature and velocity

    Energy Technology Data Exchange (ETDEWEB)

    Butterworth, D. [HTFS, Hyprotech, Didcot (United Kingdom)

    2002-07-01

    Shell-and-tube heat exchangers are normally designed on the basis of a uniform and constant fouling resistance that is specified in advance by the exchanger user. The design process is then one of determining the best exchanger that will achieve the thermal duty within the specified pressure drop constraints. It has been shown in previous papers [Designing shell-and-tube heat exchangers with velocity-dependant fouling, 34th US national Heat Transfer Conference, 20-22 August 2000, Pittsburg, PA; Designing shell-and-tube heat exchangers with velocity-dependant fouling, 2nd Int. Conf. on Petroleum and Gas Phase Behavior and Fouling, 27-31 August 2000, Copenhagen] that this approach can be extended to the design of exchangers where the design fouling resistance depends on velocity. The current paper briefly reviews the main findings of the previous papers and goes on to treat the case where the fouling depends also on the local temperatures. The Ebert-Panchal [Analysis of Exxon crude-oil, slip-stream coking data, Engineering Foundation Conference on Fouling Mitigation of Heat Exchangers, 18-23 June 1995, California] form of fouling rate equation is used to evaluate this fouling dependence. When allowing for temperature effects, it becomes difficult to divorce the design from the way the exchanger will be operated up to the point when the design fouling is achieved. However, rational ways of separating the design from the operation are proposed. (author)

  13. 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.

  14. An experimental study on accelerated fouling of aluminum oxide and ferric oxide particles in internally enhanced tubes

    Energy Technology Data Exchange (ETDEWEB)

    Abedin, Mohammad Zoynal; Kim, Nae Hyun [School of Mechanical System Engineering, Incheon National University, Incheon (Korea, Republic of)

    2016-12-15

    This paper describes the results of accelerated particulate fouling tests performed on three enhanced tubes and a plain tube. The tests were performed using ferric oxide and aluminum oxide as foulant materials. Three enhanced tubes included 25 start, 10 start helically ribbed tubes and a ripple tube. Effects of the water velocity (0.9 to 1.8 m/s) and foulant concentration (750 to 2500 ppm) were investigated. At 750 ppm, the enhanced tubes fouled almost the same as the plain tube for the entire velocity range tested (0.9 to 1.8 m/s). The enhanced tube fouled faster than the plain tube for cases of high concentration combined with low velocities. Of the three enhanced tubes, the 25 start helically ribbed tube fouled faster than the ripple and the 10 start helically ribbed tubes. One thing to be noted is that the fouling concentrations used in the tests are significantly higher than would be expected in commercial heat exchangers. Also, the velocity range investigated is lower than would be expected in heat exchanger operation.

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

    International Nuclear Information System (INIS)

    Nicolas, G.; Mateo, M.P.; Yanez, A.

    2007-01-01

    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

  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)

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

    2015-01-01

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

  17. Numerical Investigation of Simultaneously Deposition and Re-Entrainment Fouling Processes in Corrugated Tubes by Coupling CFD and DEM

    DEFF Research Database (Denmark)

    Hærvig, Jakob; Condra, Thomas Joseph; Sørensen, Kim

    The deposition of particulate fouling on flue gas heat exchanger surfaces results in decreased heat transfer. Even though an increasingly amount of work is done on the design of clean heat exchanger surfaces, the effect of fouling remains a challenge. As some heat exchanger designs are more prone...... to fouling deposit than others, detailed fouling considerations have to be taken into account in the initial design process of new heat exchangers. This study presents initial simulations of particulate fouling in the corrugated tube heat exchanger type. Using a mechanistic Euler-Lagrange approach, where...... Computational Fluid Dynamics (CFD) software OpenFOAM is coupled to the Discrete Element Method (DEM) software LIGGGHTS using the coupling software CFDEM. A four-way coupling is used to model fluid-particle and particle-particle interactions and thereby allowing for a particle fouling layer to build up along...

  18. Superheater fouling in a BFB boiler firing wood-based fuel blends

    NARCIS (Netherlands)

    Stam, A.F.; Haasnoot, K.; Brem, Gerrit

    2014-01-01

    Four different fuel blends have been fired in a 28 MWel BFB. Wood pellets (test 0) were not problematic for about ten years, contrary to a mixture of demolition wood, wood cuttings, compost overflow, paper sludge and roadside grass (test 1) which caused excessive fouling at a superheater bundle

  19. Application and verification of cold air velocity technique for solving tube ash erosion problem in PC boilers

    International Nuclear Information System (INIS)

    Yoo, Kisoo; Jeong, Kwon Seok

    2012-01-01

    Fly ash erosion is a leading cause of boiler tube failure in PC boilers. Therefore, shields or baffle plates are installed in specific areas to mitigate fly ash erosion and prevent boiler tube failure. However, the tube failure problems caused by fly ash erosion cannot be eliminated with this solution alone, because each PC boiler has a different flue gas flow pattern and erosion can become severe in unexpected zones. This problem is caused by an asymmetric internal flow velocity and local growth of the flue gas velocity. For these reasons, clearly defining the flow pattern in PC boilers is important for solving the problem of tube failure caused by fly ash erosion. For this purpose, the cold air velocity technique (CAVT) can be applied to the fly ash erosion problem. In this study, CAVT was carried out on the Hadong 2 PC boiler and the feasibility of application of CAVT to conventional PC boilers was validated

  20. Alloy 33 weld overlay extends boiler tube life and saves money

    Energy Technology Data Exchange (ETDEWEB)

    Paul, L.; Clark, G.; Ossenberg-Engels, A. [ThyssenKrupp VDM (United States)

    2007-09-15

    Low-NOx burners installed in coal-fired utility boilers cause problems with boiler tube cracking. Materials with increased corrosion resistance such as the new Alloy 33 should be more resistant to this type of 'circumferential cracking'. Alloy 33 is cheaper and has lower nickel and molybdenum content than the traditional Alloy 622 and 625. The article describes extensive corrosion testing experiments carried out by ThyssenKrupp VDM on Alloy 33 and Alloy 622. In the lab, in environments representative of coal-fired boilers operating under low-NOx combustion conditions, Alloy 33 was found to be better than Alloy 622. Field tests compared Alloy 33 and Alloy 622 in two supercritical tangentially-fired boilers and one tangentially-fired high pressure drum boiler. After up to 23 months of exposure there was no evidence of cracks and only slight evidence of corrosion in Alloy 33. 1 fig., 2 tabs., 2 photos.

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

    International Nuclear Information System (INIS)

    Skinner, V.R.

    1983-01-01

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

  2. Innovative coupling of cogeneration units with fire tube boilers: thermo-fluid dynamics of the fire tubes

    Science.gov (United States)

    Cioccolanti, L.; Arteconi, A.; Bartolini, C. M.; Polonara, F.

    2017-11-01

    Nowadays the thermal energy demand in the industrial sector is usually satisfied by means of fire tube boilers while electricity is supplied from the grid. Alternatively cogeneration units could be adopted for thermal and electrical energy self-production, whilst installing boilers only as back-up units. However, even when cogeneration is profitable, it is not widespread because industries are usually unwilling to accept cogeneration plants for reliability and high investment costs issues. In this work a system aimed at overcoming the above mentioned market difficulties is proposed. It consists of an innovative coupling of a combined heat and power unit with a modified fire tube boiler. In particular, a CFD analysis was carried out by the authors in order to address the most critical aspects related with the coupling of the two systems. More precisely, the following aspects were evaluated in detail: (i) pressure losses of the exhausts going from the prime mover to the boiler due to the sudden cross-section area variations; (ii) thermal power recoverable from the exhausts in the tubes of the boiler; (iii) dependence of the system on the final users’ specification.

  3. Fouling of steam generator tubes in nuclear power plants. Laboratory tests to reproduce oxides deposition and chemical cleanings

    International Nuclear Information System (INIS)

    Goujon, C.; Bescond, A.; Mansour, C.; Delaunay, S.; Pauporte, T.; Bretelle, J-L.

    2014-01-01

    In the secondary circuit of nuclear Pressurized Water Reactors, magnetite (Fe 3 O 4 ) deposits lead to Steam Generators (SG) fouling decreasing thermal performances. As a counteraction, chemical cleanings, started in 1989, have become since 2006 the priority strategy to remove oxides deposited in SG of the EDF fleet. The use of chelating agents in chemical cleaning processes could affect the passive layer of SG tubes, and then modify their surface reactivity. To investigate this impact, a three steps R and D program was established: (1) reproduce deposits on SG tube surfaces using several techniques, (2) apply industrial chemical cleaning procedures and (3) study the redeposition of magnetite. First, SG tubes were fouled in a specific experimental loop, FORTRAND. In this device, magnetite and soluble iron were formed by carbon steel pipes corrosion in feedwater circuit representative conditions and released in the fluid. Then, corrosion products were flow-carried to the autoclave where their precipitation and deposition on heated SG tubes led to tubes fouling. Additional nickel base alloys substrates were also fouled by magnetite electrodeposition. Second, chemical cleaning processes were applied on fouled substrates and tubes in a specific experimental device, ECCLIPS. SG industrial cleaning processes timing and thermochemical conditions were strictly respected during these operations. Finally, fouling of cleaned substrates and tubes was performed in FORTRAND in the same experimental conditions as in the first step. At each step of the study, oxide composition and properties were investigated by surface characterizations. Comparison of oxide deposits before and after cleaning highlights the impact of chemical cleanings on tubes surface reactivity. (author)

  4. The Numerical Simulation Application for Fire-Tube Boiler Heating Surface Safety Evaluation

    Directory of Open Access Journals (Sweden)

    Khaustov Sergei A.

    2016-01-01

    Full Text Available The numerical simulation is applied for fire-tube boiler heating surface safety estimation. Thermal processes in an inflatable fire-tube furnace during its emergency operation were simulated using the finite volume method with Euler approximation and the implicit pressure based algorithm. Study results reproduce failures connected with increasing of impasse aerodynamic resistance. The method of these failures prediction is suggested. Simulation has shown that entering the amount of coolant into combustion volume results in burner fan incapability to overcome the impasse resistance of the furnace. The simulation results are visually confirmed during the inspection of emergency boilers.

  5. Sensing system for detection and control of deposition on pendant tubes in recovery and power boilers

    Science.gov (United States)

    Kychakoff, George [Maple Valley, WA; Afromowitz, Martin A [Mercer Island, WA; Hogle, Richard E [Olympia, WA

    2008-10-14

    A system for detection and control of deposition on pendant tubes in recovery and power boilers includes one or more deposit monitoring sensors operating in infrared regions of about 4 or 8.7 microns and directly producing images of the interior of the boiler, or producing feeding signals to a data processing system for information to enable a distributed control system by which the boilers are operated to operate said boilers more efficiently. The data processing system includes an image pre-processing circuit in which a 2-D image formed by the video data input is captured, and includes a low pass filter for performing noise filtering of said video input. It also includes an image compensation system for array compensation to correct for pixel variation and dead cells, etc., and for correcting geometric distortion. An image segmentation module receives a cleaned image from the image pre-processing circuit for separating the image of the recovery boiler interior into background, pendant tubes, and deposition. It also accomplishes thresholding/clustering on gray scale/texture and makes morphological transforms to smooth regions, and identifies regions by connected components. An image-understanding unit receives a segmented image sent from the image segmentation module and matches derived regions to a 3-D model of said boiler. It derives a 3-D structure the deposition on pendant tubes in the boiler and provides the information about deposits to the plant distributed control system for more efficient operation of the plant pendant tube cleaning and operating systems.

  6. INVESTIGATION OF FOULING DEPOSIT FORMATION DURING PASTEURIZATION OF CHILI SAUCE BY USING LAB-SCALE CONCENTRIC TUBE-PASTEURIZER

    Directory of Open Access Journals (Sweden)

    NUR ATIKA ALI

    2014-06-01

    Full Text Available This paper investigates the characteristics of fouling deposits obtained from chilli sauce pasteurization. A lab-scale concentric tube-pasteurizer was used to pasteurize the chilli sauce at 0.712 kg/min and 90±5°C. It was operated for 3 hours. Temperature changes were recorded during pasteurization and the data was used to plot the heat transfer profile and the fouling resistance profile. The thickness of the fouling deposit was also measured and the image was taken for every hour. The fouling deposit was collected at every hour to test its stickiness, hardness and flow behaviour. Proximate analysis was also performed and it shows that the fouling deposit from the chilli sauce is categorized as carbohydrate-based fouling deposits. Activation energy of chilli sauce is 7049.4 J.mole-1 which shows a greater effect of temperature on the viscosity. The hardness, stickiness of fouling deposit and the heat resistance increases as the chilli sauce continuously flows inside the heat exchanger.

  7. Utilization of coal-water fuels in fire-tube boilers

    International Nuclear Information System (INIS)

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

    1991-01-01

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

  8. 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.

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  10. Fire-tube boiler optimization criteria and efficiency indicators rational values defining

    Science.gov (United States)

    Batrakov, P. A.; Mikhailov, A. G.; Ignatov, V. Yu

    2018-01-01

    Technical and economic calculations problems solving with the aim of identifying the opportunity to recommend the project for industrial implementation are represented in the paper. One of the main determining factors impacting boiler energy efficiency is the exhaust gases temperature, as well as the furnace volume thermal stress. Fire-tube boilers with different types of furnaces are considered in the study. The fullest analysis of the boiler performance thermal and technical indicators for the following engineering problem: Q=idem, M=idem and evaluation according to η, B is presented. The furnace with the finned ellipse profile application results in the fuel consumption decrease due to a more efficient heat exchange surface of the furnace compared to other examined ones.

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

    International Nuclear Information System (INIS)

    Jacson, M.

    1977-01-01

    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 [fr

  12. Creep-Rupture Behavior of Ni-Based Alloy Tube Bends for A-USC Boilers

    Science.gov (United States)

    Shingledecker, John

    Advanced ultrasupercritical (A-USC) boiler designs will require the use of nickel-based alloys for superheaters and reheaters and thus tube bending will be required. The American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code Section II PG-19 limits the amount of cold-strain for boiler tube bends for austenitic materials. In this summary and analysis of research conducted to date, a number of candidate nickel-based A-USC alloys were evaluated. These alloys include alloy 230, alloy 617, and Inconel 740/740H. Uniaxial creep and novel structural tests and corresponding post-test analysis, which included physical measurements, simplified analytical analysis, and detailed microscopy, showed that different damage mechanisms may operate based on test conditions, alloy, and cold-strain levels. Overall, creep strength and ductility were reduced in all the alloys, but the degree of degradation varied substantially. The results support the current cold-strain limits now incorporated in ASME for these alloys for long-term A-USC boiler service.

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

    Directory of Open Access Journals (Sweden)

    Ismail Firas B.

    2016-01-01

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

  14. 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.

  15. A study on development of a plugging margin evaluation method taking into account the fouling of shell-and tube heat exchangers

    International Nuclear Information System (INIS)

    Hwang, Kyeong Mo; Jin, Tae Eun; Kim, Kyung Hoon

    2006-01-01

    As the operating time of heat exchangers progresses, fouling caused by water-borne deposits and the number of plugged tubes increase and thermal performance decreases. Both fouling and tube plugging are known to interfere with normal flow characteristics and to reduce thermal efficiencies of heat exchangers. The heat exchangers of Korean nuclear power plants have been analyzed in terms of heat transfer rate and overall heat transfer coefficient as a means of heat exchanger management. Except for fouling resulting from the operation of heat exchangers, all the tubes of heat exchangers have been replaced when the number of plugged tubes exceeded the plugging criteria based on design performance sheet. This paper describes a plugging margin evaluation method taking into account the fouling of shell-and-tube heat exchangers. The method can evaluate thermal performance, estimate future fouling variation, and consider current fouling level in the calculation of plugging margin. To identify the effectiveness of the developed method, fouling and plugging margin evaluations were performed at a component cooling heat exchanger in a Korean nuclear power plant

  16. On-line monitoring system for utility boiler diagnostics

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  17. 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.

  18. 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.

  19. Failure Analysis and Magnetic Evaluation of Tertiary Superheater Tube Used in Gas-Fired Boiler

    Science.gov (United States)

    Mohapatra, J. N.; Patil, Sujay; Sah, Rameshwar; Krishna, P. C.; Eswarappa, B.

    2018-01-01

    Failure analysis was carried out on a prematurely failed tertiary superheater tube used in gas-fired boiler. The analysis includes a comparative study of visual examination, chemical composition, hardness and microstructure at failed region, adjacent and far to failure as well as on fresh tube. The chemistry was found matching to the standard specification, whereas the hardness was low in failed tube compared to the fish mouth opening region and the fresh tube. Microscopic examination of failed sample revealed the presence of spheroidal carbides of Cr and Mo predominantly along the grain boundaries. The primary cause of failure is found to be localized heating. Magnetic hysteresis loop (MHL) measurements were carried out to correlate the magnetic parameters with microstructure and mechanical properties to establish a possible non-destructive evaluation (NDE) for health monitoring of the tubes. The coercivity of the MHL showed a very good correlation with microstructure and mechanical properties deterioration enabling a possible NDE technique for the health monitoring of the tubes.

  20. Failure Analysis and Magnetic Evaluation of Tertiary Superheater Tube Used in Gas-Fired Boiler

    Science.gov (United States)

    Mohapatra, J. N.; Patil, Sujay; Sah, Rameshwar; Krishna, P. C.; Eswarappa, B.

    2018-02-01

    Failure analysis was carried out on a prematurely failed tertiary superheater tube used in gas-fired boiler. The analysis includes a comparative study of visual examination, chemical composition, hardness and microstructure at failed region, adjacent and far to failure as well as on fresh tube. The chemistry was found matching to the standard specification, whereas the hardness was low in failed tube compared to the fish mouth opening region and the fresh tube. Microscopic examination of failed sample revealed the presence of spheroidal carbides of Cr and Mo predominantly along the grain boundaries. The primary cause of failure is found to be localized heating. Magnetic hysteresis loop (MHL) measurements were carried out to correlate the magnetic parameters with microstructure and mechanical properties to establish a possible non-destructive evaluation (NDE) for health monitoring of the tubes. The coercivity of the MHL showed a very good correlation with microstructure and mechanical properties deterioration enabling a possible NDE technique for the health monitoring of the tubes.

  1. Modificaciones en las calderas igneotubulares cubanas // Modifications in the Cuban boilers of fire tube

    Directory of Open Access Journals (Sweden)

    I. Pérez Mallea

    1998-01-01

    Full Text Available El objetivo de este trabajo es optimizar y diseñar las calderas igneotubulares nacionales, incluyendo las de inversión de llama yagua caliente. Con este fin se creo un software como soporte científico técnico que permite realizar los diferentes cálculosverificativos a través de los cuales se optimiza._________________________________________________________________________Abstract .The objective of this work is the optimizing and designing of the Cuban boilers of fire tube, including those of inverting offlame and hot water. A software have been developed as technical scientific supper for different calculations and optimizingprocess.

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

    Science.gov (United States)

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

    2018-03-01

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

  3. 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.

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

    International Nuclear Information System (INIS)

    Fajardo, M.; Perez Alcazar, G.A.; Aguilar, Y.

    1998-01-01

    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 O 2 -rich vapor atmosphere. The rusted products are stable at high temperatures

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

    International Nuclear Information System (INIS)

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

    1993-01-01

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

  6. Chemical preventive remedies for steam generators fouling and tube support plate blockages

    International Nuclear Information System (INIS)

    Alves Vieira, M.; Mayos, M.; Coquio, N.; Fourcroy, H.; Battesti, P.

    2010-01-01

    In 2006, EDF identified on several PWR units broached hole blockage on the upper Steam Generator (SG) Tube Support Plates (TSP). TSP blockage often occurs in association with secondary fouling. The units with copper alloys materials are more affected due the applied low pH 25 o C (9.20) all volatile treatment (AVT). Carbon steels materials are less protected against flow accelerated corrosion (FAC) and therefore more corrosion products enter the SGs through the final feed water (FFW). In parallel of chemical cleanings to remove oxides deposits in SGs, EDF has defined a strategy to improve operating conditions. It mainly relies on the removal of copper alloys materials to implement a high pH AVT (9.60) as a preventive remedy. However for some plants, copper alloys removal is not straightforward due to environmental constraints. EDF must indeed manage the implementation of a biocide treatment needed in closed loop cooling systems (as copper has a bacteriostatic effect on micro-organisms) and more generally must comply with discharge authorisations for chemical conditioning reagents or biocide reagent. An alternative conditioning was tested on the Dampierre 4 unit in 2007/2008 during 6 months to assess if operating at 9.40 was acceptable regarding the impacts on copper alloys materials. The perspective would be to implement it in the units where no biocide treatment can be applied on a short term. In parallel, other chemical conditionings or additives will be implemented or tested. First of all, EDF will carry out a trial test with APA in order to assess its efficiency on the removal of oxides deposits through SG blowdown. On the other hand, AVT with high pH ethanolamine (ETA) will be implemented as an alternative of ammonia and morpholine conditioning on some chosen plants. Ethanolamine is selected as a way to mitigate FAC kinetics in two-phase flow areas (reheaters or moisture heater separator) or to limit liquid releases. This paper provides the lessons of the

  7. Developing an early laekage detection system for thermal power plant boiler tubes by using acoustic emission technology

    International Nuclear Information System (INIS)

    Lee, Sang Bum; Roh, Seon Man

    2016-01-01

    A thermal power plant has a heat exchanger tube to collect and convert the heat generated from the high temperature and pressure steam to energy, but the tubes are arranged in a complex manner. In the event that a leakage occurs in any of these tubes, the high-pressure steam leaks out and may cause the neighboring tubes to rupture. This leakage can finally stop power generation, and hence there is a dire need to establish a suitable technology capable of detecting tube leaks at an early stage even before it occurs. As shown in this paper, by applying acoustic emission (AE) technology in existing boiler tube leak detection equipment (BTLD), we developed a system that detects these leakages early enough and generates an alarm at an early stage to necessitate action; the developed system works better that the existing system used to detect fine leakages. We verified the usability of the system in a 560 MW-class thermal power plant boiler by conducting leak tests by simulating leakages from a variety of hole sizes (⌀2, ⌀5, ⌀10 mm). Results show that while the existing fine leakage detection system does not detect fine leakages of ⌀2 mm and ⌀5 mm, the newly developed system could detect leakages early enough and generate an alarm at an early stage, and it is possible to increase the signal to more than 18 dB

  8. Simulation of heat transfer in combustion chamber waterwall tubes of supercritical steam boilers

    Directory of Open Access Journals (Sweden)

    Grądziel Sławomir

    2016-06-01

    Full Text Available The paper presents the results of numerical computations performed for the furnace chamber waterwalls of a supercritical boiler with a steam output of 2400 × 103 kg/h. A model of distributed parameters is proposed for the waterwall operation simulation. It is based on the solution of equations describing the mass, momentum and energy conservation laws. The aim of the calculations was to determine the distribution of enthalpy, mass flow and fluid pressure in tubes. The balance equations can be brought to a form where on the left-hand side space derivatives, and on the right-hand side – time derivatives are obtained. The time derivatives on the right-hand side were replaced with backward difference quotients. This system of ordinary differential equations was solved using the Runge-Kutta method. The calculation also takes account of the variable thermal load of the chamber along its height. This thermal load distribution is known from the calculations of the heat exchange in the combustion chamber. The calculations were carried out with the zone method.

  9. 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

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

    International Nuclear Information System (INIS)

    Herszage, A.; Toren, M.

    1998-01-01

    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

  11. Effects of Different Fuel Specifications and Operation Conditions on the Performance of Coated and Uncoated Superheater Tubes in Two Different Biomass-Fired Boilers

    DEFF Research Database (Denmark)

    Wu, Duoli; Dahl, Kristian V.; Madsen, Jesper L.

    2018-01-01

    Fireside corrosionis a serious concern in biomass firing powerplants such that the efficiency of boilers is limited by high temperature corrosion. Application of protective coatings on superheater tubes is a possible solution to combat fireside corrosion. The current study investigates the corros......Fireside corrosionis a serious concern in biomass firing powerplants such that the efficiency of boilers is limited by high temperature corrosion. Application of protective coatings on superheater tubes is a possible solution to combat fireside corrosion. The current study investigates...... the corrosion performance of coated tubes compared to uncoated Esshete 1250 and TP347H tubes, which were exposed in two different biomass-fired boilers for one year. Data on the fuel used, temperature of the boilers, and temperature fluctuations are compared for the two boilers, and how these factors influence...... thermal cycling took place, both the Ni and Ni2Al3 coatings failed. This highlights the differences between the two biomass plants and demonstrates thata coating solution has to be tailored to the operation conditions of a specific boiler....

  12. 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)

  13. Effect of Prolong Aging to the Microstructure and Mechanical Properties of Boiler Tube

    International Nuclear Information System (INIS)

    Norasiah Abdul Kasim; Mohd Harun; Muhamad Rawi Mohd Zin; Zaifol Samsu; Mahdi Ezwan Mahmoud; Zaiton Selamat; Shariff Satar

    2013-01-01

    Boiler or steam generator is a device used to create steam by applying heat energy to water. For industrial applications, most boilers are used under extreme conditions, which require them to operating continuously or in a batch. Therefore constant heating and cooling will result into certain material failure, or when the operation itself exhibit a few malfunctions, it will affected the boiler condition and contribute to its failure. Hence the main emphasis on this study is investigating the effect of aging, with the influence of temperature by heating it into a period of time. Focus on understanding the changes occurred during the operating hour of boiler by simulating a short term aging experiment. The boilers structure material, Carbon Steel BS3509 used in this experiment were heated on a furnace with 500 and 550 centigrade for 19, 49, 72 and 191 hours. After the heating process, the metal specimens will be observed its micro structural changes and the oxide layer. The hardness will also be tested and taken accounted for before and after heating. The results and insight from the observation have been analyzed and discussed. (author)

  14. Simulation of Working Processes in the Water-Tube Boiler Furnace with the Purpose of Reducing Emissions of Nitrogen Oxides

    Directory of Open Access Journals (Sweden)

    Redko A.A.

    2017-04-01

    Full Text Available A significant number of domestic and industrial boilers are in operation in Ukraine. Nitrogen oxides are the most dangerous among all combustion products that pollute the atmosphere, therefore, one should take some measures for decreasing the formation of nitrogen oxides during combustion. The studies were carried out at the boilers of low power (100 kW with a tubular radiator and an open end. The studies in the furnaces of industrial steam boilers having a tubular radiator with a closed end have not been done. The numerical study results of the gaseous fuel combustion processes in the furnace of a DE-10/14 steam water-tube boiler are presented. The fuel-air mixture is formed by premixing the 15% part of the air with a primary burner twist factor n=2.4 and a secondary burner twist factor n=1.6, and an air excess factor αв=10. As a result of the studies, the temperature and velocity distributions of gases in the combustion chamber, the density of heat flows on the screen tubular surfaces, and the concentrations of the combustion components were determined. Flue gas recirculation in the volume of 80-100% is provided, and the reversible movement of combustion products towards the combustion front provides a reduction in the concentration of nitrogen oxides up to 123-125 mg/m3 at the furnace outlet. Disadvantages are the following: the formation of stagnant zones near the end of the secondary radiator. The optimum diameter of the tubular radiator equals to two burners diameters and tubular radiator is located at a distance of one meter from the burner cutoff.

  15. 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.

  16. Relaxation and corrosion resistance of alloy 800 used for steam generator tubes of ship borne boilers

    International Nuclear Information System (INIS)

    Corrieu, J.M.; Cortial, F.; Maillard, J.L.; Vernot-Loier, C.; Lebeau, M.

    1994-01-01

    The INCO ''INCOLOY 800'' trademark groups the Fe-Cr-Ni alloys containing 30 to 35% nickel, 19 to 23% chromium, 0,15 to 0,60% aluminium, 0,15 to 0,60% titanium and less than 0,10% carbon contents, used as construction materials for condenser and heat exchanger tubes. In parallel with water chemistry control and studies aimed at reducing the residual stresses resulting from tube expansion, studies have been conducted to a better understanding of this alloy, its metallurgy and its corrosion behaviour under accurately defined fabrication and heat treatment conditions. The purpose of this paper is to present the results of a behaviour study of INDRET alloy 800 concerning isothermal relaxation and effects of the said relaxation heat treatments on alloy microstructure studied with a transmission electron-chemical method to determine the sensitiveness to intergranular corrosion, and by electrochemistry in pressurized hot water. (authors). 4 figs., 5 tabs., 7 refs

  17. Experimental and numerical investigation of gas side particulate fouling onto heat exchanger tubes; Etude des differents mecanismes de depot conduisant a l'encrassement particulaire en phase gazeuse des tubes d'echangeurs de chaleur

    Energy Technology Data Exchange (ETDEWEB)

    Bailer, F.

    1998-11-06

    This works deals with gas side particulate fouling onto heat exchanger tubes. An experimental and numerical investigation was carried out. By means of a new testing loop designed for this study the deposit kinetics were obtained in dust-controlled conditions at the beginning of the fouling process, Experimental results pointed out the existence of various transport regimes: for sub-micron particles, convective diffusion augmented by thermophoresis in the presence of a temperature gradient governs the particle deposition: inertial impaction controls the super-micron particles deposition, in the intermediate granulometric range, combined action of particle inertia and thermophoresis must be considered. Moreover, measurements on an other testing loop using a more concentrated aerosol allowed us to point out the modification of the mechanisms with time and the influence of the deposit shape. A numerical model predicting the particle deposition, based on the TRIO software and an Eulerian-Lagrangian approach, was developed and validated against experimental results from the literature and from our study. Numerical approach gave us an accurate understanding of the phenomena by means of local parameters computations. In this way, the different mechanisms which control particulate deposition onto heat exchangers tubes were identified and modeled, especially before the onset of the inertial impaction. (authors)

  18. A study on the concentration of CO by the length and the variation of the bent tube of the exhaust pipe for a household gas boiler

    International Nuclear Information System (INIS)

    Leem, Sa Hwan; Huh, Yong Jeong; Lee, Jong Rark

    2008-01-01

    Energy and environment become increasingly serious after the industrial revolution. The demand for gas as an ecofriendly energy source is also increasing. With the demand, the installation and the use of gas boilers have also increased, so the damage to human life by the waste gas (CO and CO 2 ) continues increasing every year. Hence, the aim of this study was to investigate the concentration of CO (Carbon Monoxide) by the length and the variation of the bent tube of the exhaust pipe by installing a boiler with the same method as a household boiler and to discover the harm to humans. For the effect of the length, the allowable concentration of CO is 50ppm, and the 3m of the once bent tube starts exceeding the allowable concentration of CO after 5 minutes, and the 4m and 5m starts exceeding after 3 minutes. In addition, the 1m of three times bent tube starts exceeding the allowable concentration of CO after 3 minutes

  19. INVESTIGATION OF FOULING EFFECT ON OVERALL ...

    African Journals Online (AJOL)

    Fouling is one of the major problems confronting heat exchangers in most industries. Shell and tube heat exchangers are perhaps the most common types of heat exchangers in industrial applications due to their flexibility and versatility. This study investigated the effect of fouling on the performance of the shell and tube ...

  20. Development of 9CrW tube, pipe and forging for ultra supercritical power plant boilers; Boiler yo kokyodo 9CrW kokan oyobi tankohin (NF616) no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Ogami, M.; Mimura, H.; Naoi, H. [Nippon Steel Corp., Tokyo (Japan); Kinbara, S. [Daido Steel Co. Ltd., Nagoya (Japan); Fujita, T. [The University of Tokyo, Tokyo (Japan); Ikemoto, T.

    1997-02-07

    This paper describes development of 9CrW steel (NF616) for ultra-supercritical power plant boilers, and properties of the NF616 tube, pipe and forging. Chemical composition of NF616 is featured by including W which has not been added to previous heat resistant materials. W addition contributes to solid solubility and precipitation strengthening, and improves creep rupture strength. Metallic texture of NF616 is also based on tempered single-phase martensite texture to improve rupture strength and toughness. The high-temperature tensile test result showed that the NF616 tube, pipe and forging satisfy the minimum standard values of cold tensile characteristics enough, such as tensile strength of 620MPa, 0.2% proof stress of 440MPa and elongation of 20%. In the Charpy impact test after long time aging at 600{degree}C, the small and medium NF616 pipes showed the toughness more than 100J/cm{sup 2} at 20{degree}C which is sufficient for boiler materials. Even the large pipe and forging showed the toughness of nearly 200J/cm{sup 2} at 20{degree}C after heat treatment. 14 refs., 11 figs., 3 tabs.

  1. Ultrasonic water level determination of the high-pressure boilers tubes; Determinacao do nivel d'agua em tubos verticais de caldeiras aquatubulares por ultra-som

    Energy Technology Data Exchange (ETDEWEB)

    Goettems, Felipe Samuel; Reolon, Amon Marques; Avancini, Flavio; Braga, Rubem Manoel de; Reguly, Afonso [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Lab. de Metalurgia Fisica], e-mail: fgoettems@demet.ufrgs.br

    2006-07-01

    Electric power is very important to our society and thermoelectric power plant. They are especially important mainly in the summer when there is a scarcity in water supply to hydroelectric power plants. Southern Brazilian thermoelectric power plants employ high-pressure boilers in order to generate water vapor which, in turn, moves turbines to produce electricity. These high-pressure boilers must work in a continuous way to avoid damages caused by emergency halts. To accomplish this, some actions must be taken. The water height inside of the tubes must be kept in a strict level to avoid thermal gradient in both water walls and super-heater header. In this water walls the water become in vapor. The best way to regulate the valves that command the water level is through the control of the water height and this is the main purpose of this work. The ultrasound is a nondestructive test which is able in doing this control without damaging the tube. This method allows determining the water level, improving the system performance and reducing the maintenance costs caused by tube collapse. (author)

  2. MODELLING, SIMULATING AND OPTIMIZING BOILERS

    DEFF Research Database (Denmark)

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

    2003-01-01

    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 possible. Due...

  3. Improvement of fire-tube boilers calculation methods by the numerical modeling of combustion processes and heat transfer in the combustion chamber

    Science.gov (United States)

    Komarov, I. I.; Rostova, D. M.; Vegera, A. N.

    2017-11-01

    This paper presents the results of study on determination of degree and nature of influence of operating conditions of burner units and flare geometric parameters on the heat transfer in a combustion chamber of the fire-tube boilers. Change in values of the outlet gas temperature, the radiant and convective specific heat flow rate with appropriate modification of an expansion angle and a flare length was determined using Ansys CFX software package. Difference between values of total heat flow and bulk temperature of gases at the flue tube outlet calculated using the known methods for thermal calculation and defined during the mathematical simulation was determined. Shortcomings of used calculation methods based on the results of a study conducted were identified and areas for their improvement were outlined.

  4. 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.

  5. ECUT energy data reference series: boilers

    Energy Technology Data Exchange (ETDEWEB)

    Chockie, A.D.; Johnson, D.R.

    1984-09-01

    Information on the population and fuel consumption of water-tube, fire-tube and cast iron boilers is summarized. The use of each boiler type in the industrial and commercial sector is examined. Specific information on each boiler type includes (for both 1980 and 2000) the average efficiency of the boiler, the capital stock, the amount of fuel consumed, and the activity level as measured by operational load factor.

  6. Assessment of factors affecting boiler tube lifetime in waste-fired generators: New opportunities for research and technology development

    Energy Technology Data Exchange (ETDEWEB)

    Wright, I.; Krause, H.H. [Battelle, Columbus, OH (United States)

    1996-07-01

    The disposal of municipal solid waste (MSW) is a major problem in numerous communities in the United States. In this country, approximately 195.7 million tons of MSW were produced in 1990 of which 17 percent was recovered for recycling or composting, 16 percent was combusted, and about 67 percent was disposed of in landfills. This paper discusses the combustion of refuse derived fuels and municipal wastes. The corrosion of the alloys used in boilers is described.

  7. Fouling reduction characteristics of a no-distributor-fluidized-bed heat exchanger for flue gas heat recovery

    Energy Technology Data Exchange (ETDEWEB)

    Jun, Y.D.; Lee, K.B.; Islam, S.Z.; Ko, S.B. [Kongju National University, Kong Ju (Republic of Korea). Dept. for Mechanical Engineering

    2008-07-01

    In conventional flue gas heat recovery systems, the fouling by fly ashes and the related problems such as corrosion and cleaning are known to be major drawbacks. To overcome these problems, a single-riser no-distributor-fluidized-bed heat exchanger is devised and studied. Fouling and cleaning tests are performed for a uniquely designed fluidized bed-type heat exchanger to demonstrate the effect of particles on the fouling reduction and heat transfer enhancement. The tested heat exchanger model (1 m high and 54 mm internal diameter) is a gas-to-water type and composed of a main vertical tube and four auxiliary tubes through which particles circulate and transfer heat. Through the present study, the fouling on the heat transfer surface could successfully be simulated by controlling air-to-fuel ratios rather than introducing particles through an external feeder, which produced soft deposit layers with 1 to 1.5 mm thickness on the inside pipe wall. Flue gas temperature at the inlet of heat exchanger was maintained at 450{sup o}C at the gas volume rate of 0.738 to 0.768 CMM (0.0123 to 0.0128 m{sup 3}/sec). From the analyses of the measured data, heat transfer performances of the heat exchanger before and after fouling and with and without particles were evaluated. Results showed that soft deposits were easily removed by introducing glass bead particles, and also heat transfer performance increased two times by the particle circulation. In addition, it was found that this type of heat exchanger had high potential to recover heat of waste gases from furnaces, boilers, and incinerators effectively and to reduce fouling related problems.

  8. 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)

  9. MODELLING, SIMULATING AND OPTIMIZING BOILERS

    DEFF Research Database (Denmark)

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

    2003-01-01

    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...... to the internal pressure the consequence of the increased volume (i.e. water-/steam space) is an increased wall thickness in the pressure part of the boiler. The stresses introduced in the boiler pressure part as a result of the temperature gradients are proportional to the square of the wall thickness...... 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...

  10. 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.

  11. Optimizing the Integrated Design of Boilers - Simulation

    DEFF Research Database (Denmark)

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

    2004-01-01

    Boilers can be considered as consisting of three main components: (i) the pressure part, (ii) the burner and (iii) the control system. To be able to develop the boilers of the future (i.e. the boilers with the lowest emissions, the highest efciency, the best dynamic performance etc....... 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...... into account. The present study covers re-tube boilers. To be able to minimize the size (i.e. volume) of the boiler and, at the same time, obtain the best possible dynamic performance, it is important to minimize the water level uctuations in the boiler as much as possible. In the present study a detailed...

  12. Fouling of Structured Surfaces during Pool Boiling of Aqueous Solutions

    International Nuclear Information System (INIS)

    Esawy, M.

    2011-01-01

    Bubble characteristics in terms of density, size, frequency and motion are key factors that contribute to the superiority of nucleate pool boiling over the other modes of heat transfer. Nevertheless, if heat transfer occurs in an environment which is prone to fouling, the very same parameters may lead to accelerated deposit formation due to concentration effects beneath the growing bubbles. This has led heat exchanger designers frequently to maintain the surface temperature below the boiling point if fouling occurs, e.g. in thermal seawater desalination plants. The present study investigates the crystallization fouling of various structured surfaces during nucleate pool boiling of CaSO 4 solutions to shed light into their fouling behaviour compared with that of plain surfaces for the same operating conditions. As for the experimental part, a comprehensive set of clean and fouling experiments was performed rigorously. The structured tubes included low finned tubes of different fin densities, heights and materials and re-entrant cavity Turbo-B tube types.The fouling experiments were carried out at atmospheric pressure for different heat fluxes ranging from 100 to 300 k W/m 2 and CaSO 4 concentrations of 1.2 and 1.6 g/L. For the sake of comparison, similar runs were performed on plain stainless steel and copper tubes.Overall for the finned tubes, the experimental results showed a significant reduction of fouling resistances of up to 95% compared to those of the stainless steel and copper plain tubes. In addition, the scale formation that occurred on finned tubes was primarily a scattered and thin crystalline layer which differs significantly from those of plain tubes which suffered from a thick and homogenous layer of deposit with strong adhesion. Higher fin densities and lower fin heights always led to better antifouling performance for all investigated finned tubes. It was also shown that the surface material strongly affects the scale formation of finned tubes i

  13. EDF approach for fouling mitigation

    International Nuclear Information System (INIS)

    Dijoux, M.; Nordmann, F.; Stutzmann, A.

    2001-01-01

    The situation and evolution of fouling of steam generator tubing are described in the 58 French PWR units, and the different studies and actions carried out to try to solve the problem and avoid any power output reduction associated to pressure drop. The remedies include the selection of the best secondary water treatment with amines such as morpholine in order to minimise corrosion product transport as well as mechanical remedies such as sludge lancing or chemical cleaning. Other options like dispersant addition are under evaluation. (R.P.)

  14. Fluoroelastomer Fouling Release Coating

    National Research Council Canada - National Science Library

    Malik, Aslam

    1998-01-01

    Our goal is to develop novel fluoroelastomers that exhibit fouling release capabilities and to understand the polymer characteristics that influence the adhesion of biofouling organisms to polymeric substrates...

  15. Chemical cleaning of UK AGR boilers

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  16. Two-phase forced-convective fouling under steam generator operating conditions

    International Nuclear Information System (INIS)

    Klimas, S.J.; Pietralik, J.M.

    2002-01-01

    Two-phase forced-convective fouling can occur in adiabatic two-phase flow and in diabatic two-phase flow, where it can be a significant contributor to fouling under flow-boiling conditions. For recirculating steam generators (SGs), it is, therefore, of significance to steam separators, tube support plates, tubesheet and the tube bundle. Loop test data are presented on forced-convective fouling rate of iron corrosion products under a range of conditions relevant to the secondary-side of recirculating SGs. The measurements were performed using a number of corrosion products (magnetite, hematite and lepidocrocite) under a range of water chemistry conditions, with several different amines. The measurements were limited to the straight-tube geometry. Comparable fouling data are given for flow-boiling conditions. A SG artefact was examined to corroborate the loop data. The rate constants for the forced-convective fouling measurements are compared with those for flow-boiling fouling. Their relative magnitudes can vary greatly, depending on the chemistry and thermohydraulic conditions. Boiling fouling dominated over forced-convection fouling for hematite and lepidocrocite particles, likely because of particle-bubble interactions. Forced-convective fouling rate was only slightly lower than boiling fouling for magnetite. For the region of cross-flow (upper tube bundle), deposits show significant thickness variation. Four or five deposit thickness peaks are noted, approximately equally spaced circumferentially. It is hypothesized that the fouling pattern is developed due to the cross-flow pattern present in the tube bundle. The possible interactions between the force-convective and nucleate-boiling fouling streams are briefly discussed. A method is presented for the superposition of the forced-convective and nucleate boiling fouling components. This method is based on the Chen heat transfer correlation. (author)

  17. 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.

  18. 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.)

  19. 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

  20. Experimental study of particulate fouling onto heat exchanger elements

    International Nuclear Information System (INIS)

    Chandrasa

    1994-01-01

    An experimental study of particulate fouling onto tubular heat exchanger surfaces was carried out using sodium sulfate particles. An experimental apparatus equipped with an aerosol generator has been used to examine the deposition of small particles under controlled conditions. Two sets of experiments were performed. Firstly, the deposition against time of solid particles onto single heat exchanger tube in cross-flow was studied. The effects of a number variables such as particle size, gas velocity and temperature on the deposition was analysed. Secondly, the deposition for the aerosol particles as they passed through a bank of finned tubes was examined. The deposition patterns on various tubes depended on local conditions (velocity and temperature) within the bank. It was found that the fouling resistance increases as aerosol flow rate decreases. The smaller particles showed higher fouling resistance. (author) [fr

  1. Application of electrochemical impedance spectroscopy to monitor seawater fouling on stainless steels and copper alloys

    International Nuclear Information System (INIS)

    Feron, D.

    1991-01-01

    Electrochemical impedance spectroscopy may be applied to detect and to follow seawater fouling. Experiments have been conducted with natural seawater flowing inside tube-electrodes at temperatures between 30 deg C and 85 deg C. With stainless steel tubes, mineral and organic foulings have been followed; a linear relationship between the dry weight of the organic fouling and its electrical resistance, has been observed. On copper alloy tubes, only mineral deposits have occurred and so have been detected by impedance spectroscopy. (Author). 5 refs., 6 figs

  2. Mitigation of crude oil preheat train fouling by design

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, D.I.; Polley, G.T.; Pugh, S.J.

    2002-07-01

    Fouling in crude oil preheat trains is a significant industrial problem which has restricted the application of process integration techniques such as ''pinch technology'' in this sector. A semiempirical fouling model for crude oil fouling developed by Panchal and co-workers allows the effects of fouling to be considered at the design stage for such networks. Application of this model at three levels - (1) design of new networks; (2) retrofitting of existing systems; and (3) identification of robust specifications for individual heat exchanger units - is discussed. The design issues are discussed using case studies illustrated by a graphical construction, the temperature field plot. Rigorous optimization of the final designs is not reported. The specification discussion describes how the crude fouling model can be incorporated into existing heat exchanger design software to identify exchanger configurations which are less likely to experience significant fouling over a range of operating conditions. This article concentrates on shell-and-tube designs, but the concepts will be applicable to other exchanger types once a suitable fouling model becomes available. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    Sharp, William (Sandy) [SharpConsultant

    2011-12-01

    the measured first melting point of fly ash deposits does not necessarily produce a step increase in corrosion rate. Corrosion rate typically accelerates at temperatures below the first melting temperature and mixed deposits may have a broad melting temperature range. Although the environment at a superheater tube surface is initially that of the ash deposits, this chemistry typically changes as the deposits mature. The corrosion rate is controlled by the environment and temperature at the tube surface, which can only be measured indirectly. Some results are counter-intuitive. Two boiler manufacturers and a consortium have developed models to predict fouling and corrosion in biomass boilers in order to specify tube materials for particular operating conditions. It would be very useful to compare the predictions of these models regarding corrosion rates and recommended alloys in the boiler environments where field tests will be performed in the current program. Manufacturers of biomass boilers have concluded that it is more cost-effective to restrict steam temperatures, to co-fire biofuels with high sulfur fuels and/or to use fuel additives rather than try to increase fuel efficiency by operating with superheater tube temperatures above melting temperature of fly ash deposits. Similar strategies have been developed for coal fired and waste-fired boilers. Additives are primarily used to replace alkali metal chloride deposits with higher melting temperature and less corrosive alkali metal sulfate or alkali aluminum silicate deposits. Design modifications that have been shown to control superheater corrosion include adding a radiant pass (empty chamber) between the furnace and the superheater, installing cool tubes immediately upstream of the superheater to trap high chloride deposits, designing superheater banks for quick replacement, using an external superheater that burns a less corrosive biomass fuel, moving circulating fluidized bed (CFB) superheaters from the

  4. Increasing the thermal efficiency of boiler plant

    Directory of Open Access Journals (Sweden)

    Uyanchinov Evgeniy

    2017-01-01

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

  5. Use of crude oil fouling threshold data in heat exchanger design

    Energy Technology Data Exchange (ETDEWEB)

    Polley, G.T. [Ulverston, Cumbria (United Kingdom); Wilson, D.I.; Yeap, B.L. [University of Cambridge, (United Kingdom). Department of Chemical Engineering; Pugh, S.J. [ESDU International plc, London (United Kingdom)

    2002-07-01

    The existence of a 'threshold' below which chemical reaction fouling of heat transfer surfaces by crude oil does not occur has been identified by Ebert and Panchal [Fouling Mitigation of Industrial Heat-Exchange Equipment, Begell House, 1997, 451-460] and clearly demonstrated by Knudsen et al. [Understanding Heat Exchanger Fouling and its Mitigation, Begell House, 265-272]. This phenomenon has important implications for the design and operation of heat exchangers in refinery pre-heat trains used for the processing of crudes. In this paper we show how a consideration of the fouling threshold condition can be incorporated into the design procedures for shell-and-tube heat exchangers. We then proceed to show how fouling can be mitigated through attention to heat exchanger design, particularly the choice of configuration. The cost of improperly designed units, based on the conventional use of 'fouling factors', is demonstrated. (author)

  6. Water side corrosion prevention in boilers

    International Nuclear Information System (INIS)

    Zeid, A.

    1993-01-01

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

  7. Inert tube coatings as a method to reduce deposit adhesion on superheaters; Inerta tubytbelaeggningar som metod att minska paaslagens vidhaeftning paa oeverhettare

    Energy Technology Data Exchange (ETDEWEB)

    Almark, Matts; Staalenheim, Annika; Henderson, Pamela

    2007-12-15

    In many biofuel and waste fired boilers there are significant deposit related problems. The fouling of the superheaters and other heat transfer surfaces reduces the heat transfer, which leads to increased flue gas temperatures, or might block the entire flue gas channel in extreme cases. An increasing share of waste and refuse derived fuels as well as the use of new types of biomass have led to increased problems with deposit formation. In order to minimize the formation of deposits and to maintain low flue gas temperatures the superheaters are subjected to frequent soot blowing, which in turn may lead to increased material loss of the tubes. The purpose of this project is to try to show that tube surfaces that may be regarded as inert have a 'non-stick' effect and that the fouling is reduced when the deposits do not react with the tube surface layer, and the adhesive force of the deposits are reduced. Nickel based alloy Sanicro 63, which forms a nickel oxide surface layer, and Kanthal APM, which forms an aluminum oxide surface layer, are compared with 15Mo3, a common superheater steels forming iron oxide and Sanicro 28, a stainless steel which forms iron and chromium oxides. Applied coatings are also tested, welded Alloy 625 and sprayed Kanthal APM, in order to investigate how ht application method interferes with the results from the pure material. A ceramic coating material that is claimed to give good results in waste and coal fired boilers is also tested. Tests with cooled probes, on which the tested materials are mounted, are performed in two different boilers, Haendeloe P14 representing waste fired boilers with fouling issues related to chlorine and heavy metals, and Myllykoski K7 representing a forest industry with non-corrosive sulfate containing deposits. The results show that a tube surface of a nickel-based alloy can reduce the formation of chlorine rich, partly melted deposits. No effect was shown on the dry, chlorine-free deposits. The

  8. 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...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-06-30

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

  10. 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.

  11. Milk fouling in heat exchangers

    NARCIS (Netherlands)

    Jeurnink, T.J.M.

    1996-01-01


    The mechanisms of fouling of heat exchangers by milk were studied. Two major fouling mechanisms were indentified during the heat treatment of milk: (i) the formation and the subsequent deposition of activated serum protein molecules as a result of the heat denaturation; (ii) the

  12. Model boiler studies on deposition and corrosion

    International Nuclear Information System (INIS)

    Balakrishnan, P.V.; McVey, E.G.

    1977-09-01

    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)

  13. 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...

  14. Feasibility of recovery boiler in paper and pulp industry

    International Nuclear Information System (INIS)

    Rashid, H.

    2010-01-01

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

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

    International Nuclear Information System (INIS)

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

    2001-01-01

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

  16. The Influence of the Ash from the Biomass on the Power Boiler Pollution

    Directory of Open Access Journals (Sweden)

    Alina Kowalczyk-Juśko

    2017-11-01

    Full Text Available Manufacturing units, which use biomass for combustion and cofiring, are obliged to increase the amount of biomass from agricultural sources gradually in place of timber biomass from forests. Many different species of trees that grow on arable land, bushes, grasses or perennials can be used for energy aims. A huge variety of plants, that give biomass useful in the power industry, is connected with a big diversity of physical characteristics (hardness, specific gravity, moisture content, porosity and chemical composition. It significantly affects not only the biomass calorific value but also the condition of the boilers in which it is burnt. This paper presents the results of the research concerning the influence of the process of combustion biomass from seven plant species on the boilers fouling on the basis of ash chemical composition. The indicators that we used for the analysis were: boilers slagging, the tendency of fuel to form impurities, sintering and agglomeration. There was shown a significant variation in the content of alkalies, that cause the formation of sediment on the boilers heating surfaces. The smallest risk of heating boilers fouling is associated with perennial grasses incineration, especially the ones from the Miscanthus species, that contain significant quantities of silicon monoxide, which is responsible for the heating surfaces erosion. The usage of polycarpic plants as Virginia mallow or Jerusalem artichoke may cause pollution deposition and reduce the efficiency of boilers to the greatest degree. Because of the fact that biomass of different plant species show the diversity of energy parameters and tendencies to foul boilers there is a need to select the material to the combustion carefully and also blends of biomass raw materials (or biomass with coal should be composed so that they are adapted to the boiler parameters and to the conditions of the combustion process.

  17. Chemical cleaning of AGR boilers

    International Nuclear Information System (INIS)

    Moore, S.V.; Moore, W.; Rantell, A.

    1978-01-01

    AGR boilers are likely to require post service chemical cleaning to remove accumulated oxides at intervals of 15 - 35 kh. The need to clean will be based on an assessment of such factors as the development of flow imbalances through parallel tubes induced by the formation of rough oxide surfaces, an increasing risk of localised corrosion as the growth of porous oxides proceeds and the risk of tube blockage caused by the exfoliation of steam-grown oxides. The study has shown what heterogeneous multilayer oxides possessing a range of physical and chemical properties form on the alloy steels. They include porous and compact magnetites, chromium spinels and sesquioxide. Ammoniated citric acid has been shown to remove deposited and water-grown magnetites from the carbon and alloy steels but will not necessarily remove the substituted spinels grown on the alloy steels or the potentially spalling steam-grown magnetite on the A1SI 316 superheater. Citric acid supplemented with the reducing agent glyoxal completely removes all oxides from the boiler except the protective inner spinel formed on the 316. Removal of the spinels and compact magnetites occurs more by undercutting and physical detachment than by the dissolution. (author)

  18. 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.

  19. Condensing boiler applications in the process industry

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  20. Industry SG heat-transfer fouling trends and probabilistic fouling predictions

    International Nuclear Information System (INIS)

    Up to the early 1970s, recirculating PWR steam generator (SG) designs incorporated large margins to accommodate loss of thermal efficiency due to thermally resistive tube scale layers and tube repairs. Such margins were typically 200-300 μh-ft 2 - o F/Btu (1 μh-ft 2 - o F/Btu = 1.76E 04 m 2 -K/kW). In the last 25 years, however, these values have been reduced by at least 50%. Further, many units operate with margins below the design value for several reasons: Thermal power uprates; Decreases in primary temperature; and, Reductions in feedwater iron concentrations, which have lowered heat-transfer fouling rates such that short-term changes are nearly imperceptible. As a result, the accumulated effect of heat-transfer fouling is a less important part of long-term utility planning. Accordingly, units often operate with SG heat-transfer margins of 40-80 μh-ft 2 - o F/Btu. Such margins, though usually adequate for several cycles, can be eroded over longer time periods as a result of: a) transient fouling increases that follow plant outages and are not always fully recovered, b) unintentional small primary temperature decreases within the control band that occur without setpoint changes, and c) gradual heat-transfer losses, due to tube scale buildup, that can be appreciable after several years. Against the above background, this paper provides an industry update on trends in the following areas that have been observed through DEI's analysis of several dozen units in the US and other countries: SG heat-transfer efficiency as a function of operating time and other variables such as average tube deposit thickness, feedwater iron concentration, and deposit properties; Clean SG heat-transfer efficiency trends after initial SG startup or full-bundle chemical cleaning. For example, such startups are typically accompanied by increases in fouling factor of 0-60 μh-ft 2 - o F/Btu that develop over a period of several months; and, Transient changes in heat-transfer fouling

  1. Tube to tube excursive instability - sensitivities and transients

    International Nuclear Information System (INIS)

    Brown, M.; Layland, M.W.

    1980-01-01

    A simple basic analysis of excursive instability in a boiler tube shows how it depends upon operating conditions and physical properties. A detailed mathematical model of an AGR boiler is used to conduct a steady state parameter sensitivity survey. It is possible from this basis to anticipate the effects of changes in operating conditions and changes in design parameters upon tube to tube stability. Dynamic responses of tubes operating near the stability threshold are examined using a mathematical model. Simulated excursions are triggered by imparting small abrupt pressure changes on the boiler inlet pressure. The influences of the magnitude of the pressure change, waterside friction factor and gas side coupling between tubes are examined. (author)

  2. Optimisation of Marine Boilers using Model-based Multivariable Control

    DEFF Research Database (Denmark)

    Solberg, Brian

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

  3. 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

  4. Electric utility CFB boilers

    International Nuclear Information System (INIS)

    Fairbanks, D.A.

    1991-01-01

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

  5. A global fouling factor methodology for analyzing steam generator thermal performance degradation

    International Nuclear Information System (INIS)

    Kreider, M.A.; White, G.A.; Varrin, R.D.

    1998-01-01

    Over the past few years, steam generator (SG) thermal performance degradation has led to decreased plant efficiency and power output at numerous PWR nuclear power plants with recirculating-type SGs. The authors have developed and implemented methodologies for quantitatively evaluating the various sources of SG performance degradation, both internal and external to the SG pressure boundary. These methodologies include computation of the global fouling factor history, evaluation of secondary deposit thermal resistance using deposit characterization data, and consideration of pressure loss causes unrelated to the tube bundle, such as hot-leg temperature streaming and SG moisture separator performance. In order to evaluate the utility of the global fouling factor methodology, the authors performed case studies for a number of PWR SG designs. Key results from two of these studies are presented here. Uncertainty analyses were performed to determine whether the calculated fouling factor for each plant represented significant fouling or whether uncertainty in key variables (e.g., steam pressure or feedwater flow rate) could be responsible for calculated fouling. The methodology was validated using two methods: by predicting the SG pressure following chemical cleaning at San Onofre 2 and also by performing a sensitivity study with the industry-standard thermal-hydraulics code ATHOS to investigate the effects of spatially varying tube scale distributions. This study indicated that the average scale thickness has a greater impact on fouling than the spatial distribution, showing that the assumption of uniform resistance inherent to the global fouling factor is reasonable. In tandem with the fouling-factor analyses, a study evaluated for each plant the potential causes of pressure loss. The combined results of the global fouling factor calculations and the pressure loss evaluations demonstrated two key points: 1) that the available thermal margin against fouling, which can

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

    International Nuclear Information System (INIS)

    Ozawa, Mamoru

    2000-01-01

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

  7. DYMEL code for prediction of dynamic stability limits in boilers

    International Nuclear Information System (INIS)

    Deam, R.T.

    1980-01-01

    Theoretical and experimental studies of Hydrodynamic Instability in boilers were undertaken to resolve the uncertainties of the existing predictive methods at the time the first Advanced Gas Cooled Reactor (AGR) plant was commissioned. The experiments were conducted on a full scale electrical simulation of an AGR boiler and revealed inadequacies in existing methods. As a result a new computer code called DYMEL was developed based on linearisation and Fourier/Laplace Transformation of the one-dimensional boiler equations in both time and space. Beside giving good agreement with local experimental data, the DYMEL code has since shown agreement with stability data from the plant, sodium heated helical tubes, a gas heated helical tube and an electrically heated U-tube. The code is now used widely within the U.K. (author)

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

    Science.gov (United States)

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

    2017-11-01

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

  9. 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

  10. 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.

  11. 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,...

  12. Millwright Apprenticeship. Related Training Modules. 7.1-7.9 Boilers.

    Science.gov (United States)

    Lane Community Coll., Eugene, OR.

    This packet, part of the instructional materials for the Oregon apprenticeship program for millwright training, contains nine modules covering boilers. The modules provide information on the following topics: fire and water tube types of boilers, construction, fittings, operation, cleaning, heat recovery systems, instruments and controls, and…

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

    International Nuclear Information System (INIS)

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

    2002-01-01

    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

  14. Implications of Steam Generator Fouling on the Degradation of Material and Thermal Performance

    Science.gov (United States)

    Turner, Carl W.

    Fouling of steam generators has a significant negative impact on the material and thermal performance the steam generators of pressurized water reactors. Corrosion products that originate from various components in the steam cycle of a nuclear power plant get pumped forward with the feed water to steam generators where they deposit on the tube bundle, tube support structure and the tube sheet. Heavy accumulation of deposit within the steam generator has led to some serious operational problems, including loss of thermal performance, under deposit corrosion, steam generator level oscillations, flow accelerated corrosion of carbon steel tube support plates and the failure of steam generator tubes due to high cycle fatigue.

  15. 49 CFR 214.323 - Foul time.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Foul time. 214.323 Section 214.323 Transportation... TRANSPORTATION RAILROAD WORKPLACE SAFETY Roadway Worker Protection § 214.323 Foul time. Working limits established on controlled track through the use of foul time procedures shall comply with the following...

  16. ANALISIS KEGAGALAN SOOTBLOWER TERHADAP PERPINDAHAN PANAS DI PIPA BOILER

    Directory of Open Access Journals (Sweden)

    Nurul Chandra Purnama

    2017-11-01

    Full Text Available Kementerian Energi dan Sumber Daya Mineral (ESDM menyebut konsumsi listrik nasional saat ini masih terbilang mini, yaitu seperempat dari indikator negara maju di dunia. Dengan angka 956 per Kilowatt-hour (kWh per kapita, konsumsi listrik Indonesia baru mencapai 23,9 persen dari konsumsi listrik negara maju sebanyak 4 ribu kWh per kapita. Salah satu komponen utama pada sistem pembangkit adalah boiler. Uap hasil produksi Boiler ini digunakan untuk memutar turbine yang akan menggerakkan generator guna menghasilkan listrik. Sootblower merupakan peralatan penunjang pada boiler yang berfungsi untuk membersihkan jelaga. Oleh karena itu peranan sootblower sangat penting dalam menjaga effisiensi boiler. Tujuan dari dilakukan analisis ini adalah mampu mengidentifikasi penurunan perpindahan panas yang terjadi pada pipa boiler, mengidentifikasi faktor penyebab kegagalan pada Sootblower, mengurangi energi yang terbuang akibat pengoperasian Sootblower. Metode penelitian untuk melakukan pelaksanaan analisis sootblower ini terdiri atas berbagai bagian, antara lain: studi literatur, proses pengumpulan data, kemudian data diolah dan dilakukan analisis guna mengetahui penyebab kegagalan pada sootblower. Hasil dari analisis kegagalan pada sootblower ini didapatkan bahwa sootblower gagal beroperasi karena ada masalah pada lance tube yang sering bengkok sehingga mempengaruhi proses perpindahan panas di pipa boiler, oleh sebab itu di rekomendasikan untuk penggantian material lance tube dari carbon steel A105 dengan defleksi 1,1 m menjadi chrome moly (AISI 4130 dengan defleksi 1,05 cm  dan dilakukan perawatan sootblower lebih baik dan rutin lagi.

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

    International Nuclear Information System (INIS)

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

    2012-09-01

    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

  18. MODELLING, SIMULATING AND OPTIMIZING BOILERS

    DEFF Research Database (Denmark)

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

    2004-01-01

    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 respect to drum...

  19. 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

  20. 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

  1. Contribution to the investigation concerning the fouling and washing of steam generators

    International Nuclear Information System (INIS)

    Dijoux, M.; Vito, S. de; Millet, L.

    2002-01-01

    Steam generator secondary side tube deposits affect optimal operation of the nuclear power plants. Stress corrosion cracking (ODSCC) occurs under deposits located in confined areas, in particular the tube - tube support plates crevices for 600-MA tubes. Fouling on free span of the bundle leads to thermal transfer inhibition for all type of tube alloys. Flow accelerated corrosion (FAC) and general corrosion of the feed water train components, depending on the chemical treatment applied, are the mainly responsible for the secondary fouling. An appropriate maintenance requires a good knowledge of deposits. In this context, a study program on deposits has been started covering the following points: - Spatial distribution and mass determination by Eddy Current Testing (ECT); - Composition by chemical analysis; - Characterization by micrographic analysis; - Modelling of deposition by computer code; and - Effects on thermal transfer and fouling factor calculation. These examinations bring a best understanding of fouling mechanisms and allow to act on influential parameters: chemical secondary treatment, selection of materials in the feed water train, and pollution ingress reduction. They permit to evaluate the interest to schedule cleaning operations such as lancing or chemical cleaning. (authors)

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

    Energy Technology Data Exchange (ETDEWEB)

    None

    2006-06-01

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

  4. Superclean coal-water slurry combustion testing in an oil-fired boiler

    Energy Technology Data Exchange (ETDEWEB)

    Miller, B.G.; Pisupati, S.V.; Poe, R.L.; Morrison, J.L.; Xie, J.; Walsh, P.M.; Shamanna, S.; Schobert, H.H.; Scaroni, A.W.

    1992-10-13

    The Pennsylvania State University is conducting a superclean coal-water slurry (SCCWS) program for the United States Department of Energy (DOE) and the Commonwealth of Pennsylvania with the objective of determining the capability of effectively firing SCCWS in an industrial boiler designed for oil. Penn State has entered into a cooperative agreement with DOE to determine if SCCWS (a fuel containing coal with 3.0 wt.% ash and 0.9 wt.% sulfur) can effectively be burned in an oil-designed industrial boiler without adverse impact on boiler rating, maintainability, reliability, and availability. The project will provide information on the design of new systems specifically configured to fire these clean coal-based fuels. The project consists of four phases: (1) design, permitting, and test planning, (2) construction and start up, (3) demonstration and evaluation (1,000-hour demonstration), and (4) program expansion (additional 1,000 hours of testing). The boiler testing will determine if the SCCWS combustion characteristics, heat release rate, fouling and slagging behavior, corrosion and erosion limits, and fuel transport, storage, and handling characteristics can be accommodated in an oil-designed boiler system. In addition, the proof-of-concept demonstration will generate data to determine how the properties of SCCWS and its parent coal affect boiler performance. Economic factors associated with retrofitting and operating boilers will be identified to assess the viability of future oil-to-coal retrofits.

  5. Superclean coal-water slurry combustion testing in an oil-fired boiler

    Energy Technology Data Exchange (ETDEWEB)

    Miller, B.G.; Pisupati, S.V.; Poe, R.L.; Morrison, J.L.; Xie, J.; Walsh, P.M.; Wincek, R.T.; Clark, D.A.; Scaroni, A.W.

    1993-04-21

    The Pennsylvania State University is conducting a superclean coal-water slurry (SCCWS) program for the United States Department of Energy (DOE) and the Commonwealth of Pennsylvania with the objective of determining the capability of effectively firing SCCWS in an industrial boiler designed for heavy fuel oil. Penn State has entered into a cooperative agreement with DOE to determine if SCCWS (a fuel containing coal with 3.0 wt.% ash and 0.9 wt.% sulfur) can effectively be burned in a heavy fuel oil-designed industrial boiler without adverse impact on boiler rating, maintainability, reliability, and availability. The project will provide information on the design of new systems specifically configured to fire these clean coal-based fuels. The project consists of four phases: (1) design, permitting, and test planning, (2) construction and start up, (3) demonstration and evaluation (1,000-hour demonstration), and (4) program expansion (additional 1,000 hours of testing). The boiler testing wig determine if the SCCWS combustion characteristics, heat release rate, fouling and slagging behavior, corrosion and erosion limits, and fuel transport, storage, and handling characteristics can be accommodated in an oil-designed boiler system. In addition, the proof-of-concept demonstration will generate data to determine how the properties of SCCWS and its parent coal affect boiler performance. Economic factors associated with retrofitting boilers will be identified

  6. Control Properties of Bottom Fired Marine Boilers

    DEFF Research Database (Denmark)

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

    2005-01-01

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

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  8. Dynamic Boiler Performance

    DEFF Research Database (Denmark)

    Sørensen, Kim

    for buying and selling energy has increased the focus on the dynamic operation capability, efciency, emissions etc. For optimizing the design of boilers for dynamic operation a quantication of the dynamic capability is needed. A framework for optimizing design of boilers for dynamic operation has been...... 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...... been developed as open, i.e. more dimensions and their corresponding quanti- cation can be added. In the present study the dynamic capability has been quantied and the feasible set for the optimization has been limited by means of a number of constraints. The constraints are: (i) simple constraints...

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

    Science.gov (United States)

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

    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.

  10. A study on the formation of fouling in a heat exchanging system for Han-river water as cooling water

    International Nuclear Information System (INIS)

    Sung, Sun Kyung; Suh, Sang Ho; Rho, Hyung Woon; Cho, Young Il

    2003-01-01

    Scale is formed when hard water is heated or cooled in heat transfer equipments such as heat exchangers, condensers, evaporators, cooling towers, boilers, and pipe walls. When scale deposits in a heat exchanger surface, it is traditionally called fouling. The objective of the present study is to investigate the formation of fouling in a heat exchanging system. A lab-scale heat exchanging system is built-up to observe and measure the formation of fouling experimentally. Water analyses are conducted to obtain the properties of Han river water. In the present study a microscopic observation is conducted to visualize the process of scale formation. Hardness of Han-river water is higher than that of tap water in Seoul

  11. Understanding the mechanism of iron sulfide-induced fouling in upgrading

    Energy Technology Data Exchange (ETDEWEB)

    Panchal, C.B. [United States Dept. of Energy, Chicago, IL (United States). Argonne National Laboratory

    2006-07-01

    This presentation investigated the underlying mechanisms of iron sulfide-induced fouling and coking in upgrading processes. Experiments to determine the effects of dissolved metals on the rate of fouling were reviewed. It was noted that the presence of species such as active sulfur and diolefins can enhance the effect of dissolved metals. An investigation of a high temperature fouling unit was then conducted to investigate the effect of iron acetate and theiphenol additions to stable heavy gas oil. The deposition rate became strongly dependent on temperature in the presence of the dissolved metals. Fouling deposit analyses from various parts of the refining process consistently showed high concentrations of iron and sulfur. It was observed that the threshold tube-wall temperature corresponded to the decomposition temperature of iron salts. A review of current literature indicated that there is little information on the interactive effects of the thermal stability of dissolved organo-metallic compounds and the reactivity of organic species in generating fouling precursors. The creation of a predictive model of threshold fouling and coking conditions was recommended. It was suggested that the model should be used during the design phases of furnaces and heat exchangers. Other recommendations included the use of on-line sensors to detect iron sulfide formulation; and the monitoring of coking furnaces. Blending guidelines to minimize the interactive effects of dissolved metals and active sulfur compounds were also presented. refs., tabs., figs.

  12. 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.

  13. Large boiler modularization

    Energy Technology Data Exchange (ETDEWEB)

    MacKenzie, Malcolm [Babcock and Wilcox Canada Ltd (Canada)

    2011-07-01

    This paper presents the modularization strategy in boiler manufacture of Babcock and Wilcox Canada Ltd, designed specifically to provide steam capacities up to 1,000,000 lb/hr. Designed as a solution for the oil sands market, the boiler responds to the needs of steam assisted gravity drainage (SAGD) and other in situ processes. Manufacture of three modules: furnace, superheater, and saturated module, is detailed assembly phases are shown as well as the construction sequence. The boiler is bottom-supported and features a unique modularized design that maximizes shop assembly and provides certainty to delivery and overall project schedule. Moreover, it is adaptable for all liquid and gaseous fuel types, including natural gas, produced gas and emulsified liquid fuels. This highly modular solution makes it a comprehensive solution for projects where construction risks and costs would otherwise be prohibitive. Maximum modularization of the boiler and minimal site labour are key design features, ensuring compliance with the weight and dimensional constraints of Alberta's high load corridor.

  14. Reliability Based Management of Marine Fouling

    DEFF Research Database (Denmark)

    Faber, Michael Havbro; Hansen, Peter Friis

    1999-01-01

    The present paper describes the results of a recent study on the application of methods from structural reliability to optimise management of marine fouling on jacket type structures.In particular the study addresses effects on the structural response by assessment and quantification...... and more representative marine fouling profiles for design of new structures and finally an approach is outlined on how to include inspections of marine fouling into a risk based inspection philosophy....

  15. Investigation into the hydrodynamic performance of fouling-release surfaces

    Science.gov (United States)

    Quinn, Ronan Declan

    Silicone fouling release coatings provide the only proven biocide free antifouling method, available to ship and boat operators. These surfaces rely on hydrodynamic forces for the removal of fouling and there is interest in understanding the relationship between biofouling and the hydrodynamic forces required for removal. This research investigated the feasibility of predicting the release of cylinders adhered to silicone with epoxy under hydrodynamic loading using a simple point load adhesion measurement. Adhesion and material science, fracture mechanics and hydrodynamics are complex subjects and a detailed review is presented. Experiments were designed and divided into two main categories. Laboratory measurements, which were undertaken to investigate the factors that affect the adhesion of epoxy to fouling release surfaces, and hydrodynamic experiments that were designed to understand the forces and moments imparted on known shapes. The laboratory experiments determined that the stress at failure of epoxy to a silicone fouling release type surface is determined by coating thickness, rate of loading, how the load is applied, chemistry of the interface, and the mechanical properties of the coating. The hydrodynamic experiments were conducted from a test section built into the hull of a 9 meter power vessel. Glass panels were mounted into an instrument such that the coating surface became an integral part of the boat hull. The instrument included, a pitot static tube, to measure the boundary layer velocity, a six component force balance, to measure the forces and moments imparted on these shapes, and the test glass panel. The panels were coated with a clear silicone and cylinders were adhered using epoxy to the coating. This setup enabled the interface between the silicone and epoxy to be viewed using a high speed digital video camera. From these experiments it was determined that it is possible to relatively predict the failure of a cylinder of any length and

  16. 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.

  17. The Modified Fouling Index Ultrafiltration constant flux for assessing particulate/colloidal fouling of RO systems

    NARCIS (Netherlands)

    Salinas-Rodriguez, S.G.; Amy, G.L.; Schippers, J.C.; Kennedy, M.D.

    2015-01-01

    Reliable methods for measuring and predicting the fouling potential of reverse osmosis (RO) feed water are important in preventing and diagnosing fouling at the design stage, and for monitoring pre-treatment performance during plant operation. The Modified Fouling Index Ultrafiltration (MFI-UF)

  18. Installations of SNCR on bark-fired boilers

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  19. Fluid heating by current injection tubes; Chauffage de fluides par tubes a passage de courant

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, L.S. [Societe Parmilleux (France)

    1999-04-01

    Current injection tube technology may be applied in compact fluid heating installation with a very low level of thermal inertia. The technology is particularly suitable for heating heat-sensitive fluids or those with a tendency to foul other types of installations. Specific advantages of current injection tubes include the elimination of cold spots and their reduced volume requirements. (author)

  20. In situ biofouling of ocean thermal energy conversion /OTEC/ evaporator tubes

    Science.gov (United States)

    Sasscer, D. S.; Morgan, T.; Tosteson, T. R.; Grannemann, G. N.

    1981-05-01

    The Puerto Rico Center for Energy and Environmental Research equipped a LCU facility in 1100 m of water near Punta Tuna, Puerto Rico to measure in situ biofouling of simulated Ocean Thermal Energy Conversion evaporator tubes. The system consisted of two 5052 aluminum alloy and two titanium tubes, through which a continuous flow of ocean water was maintained. The tubes were cleaned three times and the fouling resistance was measured, showing only slight differences between the tubes with respect to heat transfer loss resulting from biofouling. In all units, the average fouling rate after cleaning was greater than before cleaning, and only after the first cleaning did the aluminum units show greater fouling rates than did the titanium. The titanium units showed a progressive increase in the fouling rates with each cleaning. The subsequent average fouling rates for all units after eight months were between 4 and 4.6 x 0.000010 sq m-K/W-day.

  1. 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.

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

    Science.gov (United States)

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

    2017-12-01

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

  3. Firing a sub-bituminous coal in pulverized coal boilers configured for bituminous coals

    Energy Technology Data Exchange (ETDEWEB)

    N. Spitz; R. Saveliev; M. Perelman; E. Korytni; B. Chudnovsky; A. Talanker; E. Bar-Ziv [Ben-Gurion University of the Negev, Beer-Sheva (Israel)

    2008-07-15

    It is important to adapt utility boilers to sub-bituminous coals to take advantage of their environmental benefits while limiting operation risks. We discuss the performance impact that Adaro, an Indonesian sub-bituminous coal with high moisture content, has on opposite-wall and tangentially-fired utility boilers which were designed for bituminous coals. Numerical simulations were made with GLACIER, a computational-fluid-dynamic code, to depict combustion behavior. The predictions were verified with full-scale test results. For analysis of the operational parameters for firing Adaro coal in both boilers, we used EXPERT system, an on-line supervision system developed by Israel Electric Corporation. It was concluded that firing Adaro coal, compared to a typical bituminous coal, lowers NOx and SO{sub 2} emissions, lowers LOI content and improves fouling behavior but can cause load limitation which impacts flexible operation. 21 refs., 7 figs., 3 tabs.

  4. 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.

  5. 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

    2004-03-31

    This is the fifteenth Quarterly Technical Report for DOE Cooperative Agreement No: DE-FC26-00NT40753. 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. At AEP's Gavin Plant, data from the corrosion probes showed that corrosion rate increased as boiler load was increased. During an outage at the plant, the drop in boiler load, sensor temperature and corrosion rate could all be seen clearly. Restarting the boiler saw a resumption of corrosion activity. This behavior is consistent with previous observations made at a 600MWe utility boiler. More data are currently being examined for magnitudes of corrosion rates and changes in boiler operating conditions. Considerable progress was made this quarter in BYU's laboratory study of catalyst deactivation. Surface sulfation appears to partially suppress NO adsorption when the catalyst is not exposed to NH3; NH3 displaces surface-adsorbed NO on SCR catalysts and surface sulfation increases the amount of adsorbed NH3, as confirmed by both spectroscopy and TPD experiments. However, there is no indication of changes in catalyst activity despite changes in the amount of adsorbed NH3. A monolith test reactor (MTR), completed this quarter, provided the first comparative data for one of the fresh and field-exposed monolith SCR catalysts yet developed in this project. Measurements of activity on one of the field-exposed commercial monolith catalysts do not show significant changes in catalyst activity (within experimental error) as compared to the fresh catalyst. The exposed surface of the sample contains large amounts of Ca and Na, neither of which is present in the fresh sample, even after removal of visibly obvious fouling deposits. However, these fouling compounds do

  6. Design of Boiler Welding for Improvement of Lifetime and Cost Control

    Directory of Open Access Journals (Sweden)

    Atcharawadi Thong-On

    2016-11-01

    Full Text Available Fe-2.25Cr-1Mo a widely used material for headers and steam tubes of boilers. Welding of steam tube to header is required for production of boiler. Heat affected zone of the weld can have poor mechanical properties and poor corrosion behavior leading to weld failure. The cost of material used for steam tube and header of boiler should be controlled. This study propose a new materials design for boiler welding to improve the lifetime and cost control, using tungsten inert gas (TIG welding of Fe-2.25Cr-1Mo tube to carbon steel pipe with chromium-containing filler. The cost of production could be reduced by the use of low cost material such as carbon steel pipe for boiler header. The effect of chromium content on corrosion behavior of the weld was greater than that of the microstructure. The lifetime of the welded boiler can be increased by improvement of mechanical properties and corrosion behavior of the heat affected zone.

  7. EVALUASI KINERJA HEAT EXCHANGER DENGAN METODE FOULING F

    Directory of Open Access Journals (Sweden)

    Bambang Setyoko

    2012-02-01

    Full Text Available The performance of heat exchangers usually deteriorates with time as a result of accumulation of depositson heat transfer surfaces. The layer of deposits represents additional resistance to heat transfer and causesthe rate of heat transfer in a heat exchanger to decrease. The net effect of these accumulations on heattransfer is represented by a fouling factor Rf , which is a measure of the thermal resistance introduced byfouling.In this case, the type of fouling is the precipitation of solid deposits in a fluid on the heat transfer surface.The mineral deposits forming on the inner and the outer surfaces of fine tubes in the heat exchanger. Thefouling factor is increases with time as the solid deposits build up on the heat exchanger surface. Foulingincreases with increasing temperature and decreasing velocity.In this research, we obtain the coefisien clean overal 5,93 BTU/h.ft2.oF, Dirt factor 0,004 BTU/h.ft2 0F,Pressure drope in tube 2,84 . 10-3 Psi and pressure drope in shell 4,93 . 10-4 Psi.This result are less thanthe standard of parameter. Its means this Heat exchanger still clean relativity and can operate continousslywithout cleaning.

  8. Mod increases AGR boiler output

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  9. Heat Exchange and Fouling Analysis on a Set of Hydrogen Sulphide Gas Coolers

    Directory of Open Access Journals (Sweden)

    Andrés Adrian Sánchez-Escalona

    2017-07-01

    Full Text Available The sulphide acid coolers are tube and shell jacketed heat exchangers designed to cool down the produced gas from 416,15 K to 310,15 K in addition to separate the sulphur carried over by the outlet gas from the reactor tower. The investigation was carried out by applying the passive experimentation process in an online cooler set in order to determine the heat transfer rates and fouling based on heat resistance. It was corroborated that the operation of this equipment outside design parameters increases outlet gas temperature and liquid sulphur carryovers. Efficiency loss is caused by fouling elements in the fluid, which results in changes in the overall heat transfer rate. The linear tendency of the fouling heat resistance based on time for three gas flowrates.

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

    Directory of Open Access Journals (Sweden)

    M. A. Habib

    2013-01-01

    Full Text Available 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 conditions. The differential equations comprising the nonlinear model and governing the flow inside the boiler tubes were formulated to study different operational scenarios in terms of resulting dynamic response of critical variables. The experimental results and field data were obtained to validate the present nonlinear dynamic model. The calculations of the heat flux and the allowable steam quality were used to determine the maximum boiler swing rates at different conditions of riser tube of friction factor and heat flux. Diagrams for the influence of friction factor of the boiler tubes and the heat flux, that the tube is subjected to, on the maximum swing rate were examined.

  11. 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.

  12. Successful experience with limestone and other sorbents for combustion of biomass in fluid bed power boilers

    Energy Technology Data Exchange (ETDEWEB)

    Coe, D.R. [LG& E Power Systems, Inc., Irvine, CA (United States)

    1993-12-31

    This paper presents the theoretical and practical advantages of utilizing limestone and other sorbents during the combustion of various biomass fuels for the reduction of corrosion and erosion of boiler fireside tubing and refractory. Successful experiences using a small amount of limestone, dolomite, kaolin, or custom blends of aluminum and magnesium compounds in fluid bed boilers fired with biomass fuels will be discussed. Electric power boiler firing experience includes bubbling bed boilers as well as circulating fluid bed boilers in commercial service on biomass fuels. Forest sources of biomass fuels fired include wood chips, brush chips, sawmill waste wood, bark, and hog fuel. Agricultural sources of biomass fuels fired include grape vine prunings, bean straw, almond tree chips, walnut tree chips, and a variety of other agricultural waste fuels. Additionally, some urban sources of wood fuels have been commercially burned with the addition of limestone. Data presented includes qualitative and quantitative analyses of fuel, sorbent, and ash.

  13. Numerical simulation of a small-scale biomass boiler

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  14. Fouling distribution in forward osmosis membrane process.

    Science.gov (United States)

    Lee, Junseok; Kim, Bongchul; Hong, Seungkwan

    2014-06-01

    Fouling behavior along the length of membrane module was systematically investigated by performing simple modeling and lab-scale experiments of forward osmosis (FO) membrane process. The flux distribution model developed in this study showed a good agreement with experimental results, validating the robustness of the model. This model demonstrated, as expected, that the permeate flux decreased along the membrane channel due to decreasing osmotic pressure differential across the FO membrane. A series of fouling experiments were conducted under the draw and feed solutions at various recoveries simulated by the model. The simulated fouling experiments revealed that higher organic (alginate) fouling and thus more flux decline were observed at the last section of a membrane channel, as foulants in feed solution became more concentrated. Furthermore, the water flux in FO process declined more severely as the recovery increased due to more foulants transported to membrane surface with elevated solute concentrations at higher recovery, which created favorable solution environments for organic adsorption. The fouling reversibility also decreased at the last section of the membrane channel, suggesting that fouling distribution on FO membrane along the module should be carefully examined to improve overall cleaning efficiency. Lastly, it was found that such fouling distribution observed with co-current flow operation became less pronounced in counter-current flow operation of FO membrane process. Copyright © 2014 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

  15. Current research and development of controlling membrane fouling ...

    African Journals Online (AJOL)

    Fouling is a major problem influencing the operational performance, stability and cost of a membrane bioreactor (MBR). The composition of wastewater and biomass grown in the MBR are directly related to fouling. Many factors including operational parameters can affect the fouling process. The extent of fouling can be ...

  16. Effect of NTP Pretreatment on Thermal Resistance and Fouling Components of Oilfield Wastewater

    Science.gov (United States)

    Zhao, Jie; Li, Wenli; Zou, Longsheng; Fu, Honghun

    2018-01-01

    In order to prevent scaling in the process of oilfield wastewater evaporation, low temperature plasma is used for pretreatment of heavy oil wastewater. It reacts with the ions and radicals produced by the low-temperature plasma and then is send into the evaporator. The changes of various indexes of the distilled water and the distribution of fouling in the evaporation process of heavy oil wastewater after plasma pretreatment were studied. The results showed that the content and hardness of silica in wastewater were decreased after plasma pretreatment, which was more suitable for evaporation treatment. At the same time, the content of salt and oil in distilled water is reduced, and the quality is improved. In addition, when the steam concentration was 30∼40 times, the suspended solids in the concentrated solution of the wastewater increased significantly after the plasma treatment. Correspondingly, the fouling at the bottom of evaporator is greatly reduced. Comparing the various indexes of distilled water and the feed water index of gas injection boiler, it can be seen that the excessive oil content in distilled water is the biggest obstacle to the recovery of distilled water to boiler feed water. Low temperature plasma pretreatment can provide a quick and new way to solve the scaling problems and water quality problems in the recovery of distilled water from a large number of heavy oil wastewater.

  17. Improved nuclear boiler

    International Nuclear Information System (INIS)

    Pierart, Robert.

    1980-01-01

    The improved nuclear boiler concerned in this invention is of the kind comprising, inter alia, a nuclear reactor supported by a metallic structure and of which the vessel is at least enclosed in part by a casing acting as a protective containment integrated in this structure. It is essentially characterized in that this casing is fitted into and maintained in position in the metallic structure by removable locking devices which enable the casing to be withdrawn from the remainder of the structure. Hence, after the casing has been withdrawn or removed from the metallic structure, access to the reactor vessel is readily obtained for inspection and/or testing from without [fr

  18. Quality and nuclear boilers

    International Nuclear Information System (INIS)

    Cante, C.

    1977-08-01

    The design and manufacture of the components, assembly, erection and tests, these different stages in the making of a nuclear boiler are carried out according to very accurately defined techniques and organization. From the technical viewpoint, it is shown how standard practice, experience, tests, the respect of codes and standard specifications contribute to the quality of achievement. The organizing of the assurance of quality is exposed by more particularly bringing to mind an American text which sets forth a certain number of principles widely applied beyond the frontiers of the United States. (author)

  19. Multi-circulation boiler design

    Energy Technology Data Exchange (ETDEWEB)

    MacKenzie, Malcolm [Babcock and Wilcox Canada Ltd (Canada)

    2011-07-01

    Steam assisted gravity drainage (SAGD) requires steam, which was historically supplied by once-through steam generators (OTSG). OTSGs are now often replaced by drum boilers for steam generation. Drum boilers have a higher capacity than OTSGs and produce reduced blowdown. However, the volume of contaminants in feedwater is generally significant and ASME criteria require high-quality feedwater. The current study investigates a new design for a multi-circulation boiler that would allow cleaner steam to be generated from lower quality feedwater. In drum boilers, water circulates in one zone. By analyzing circulation fundamentals (notably heat flux and void fraction), the design of multiple circulation zones was envisaged to separate the clean water from the contaminated water. Working with distinct circulation zones would allow the quality of the steam from low quality feedwater to be improved, all the while maintaining the blowdown. The new design would result in a boiler which is easier to clean and would meet ASME criteria.

  20. An experimental study on the thermal and fouling characteristics in a washable shell and helically coiled heat exchanger by the Wilson plot method

    Energy Technology Data Exchange (ETDEWEB)

    Koo, Kyoung Min; Ahn, Young Chull [Pusan National University, Busan (Korea, Republic of); Hwang, Jun Hyeon; Hur, Hyun; Na, Byung Chul; Hwang, Yoon Jae; Kim, Byung Soon [LG Electronics, Changwon (Korea, Republic of); Lee, Jae Keun [EcoEnergy Research Institute, Busan (Korea, Republic of)

    2016-06-15

    Brazed plate heat exchangers (BPHEX) are broadly used in water source heat pump systems for their large heat transfer capacity. Despite their high heat transfer rate, their high-performance rate tends to decrease sharply, due to fouling and they cannot be cleaned. So the thermal and fouling resistances of washable Shell and helically coiled tube heat exchangers (SCHEX) are designed and experimentally investigated in this study. Heat exchangers with two different tube types are studied and compared with a brazed plate heat exchanger. The overall thermal resistance coefficient of the heat exchangers as determined by using Wilson plots is 38% lower than that of the brazed plate heat exchanger at a Reynolds number of 2460. Fouling test results revealed that regular maintenance and physical cleaning can be used to maintain the thermal resistance of fouling of the washable heat exchanger at a level equal to or less than that of the brazed plate heat exchanger.

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

    International Nuclear Information System (INIS)

    Jeffries, T.O.

    1985-01-01

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

  2. Microbial Relevant Fouling in Membrane Bioreactors: Influencing Factors, Characterization, and Fouling Control

    OpenAIRE

    Anthony G. Fane; Bing Wu

    2012-01-01

    Microorganisms in membrane bioreactors (MBRs) play important roles on degradation of organic/inorganic substances in wastewaters, while microbial deposition/growth and microbial product accumulation on membranes potentially induce membrane fouling. Generally, there is a need to characterize membrane foulants and to determine their relations to the evolution of membrane fouling in order to identify a suitable fouling control approach in MBRs. This review summarized the factors in MBRs that inf...

  3. B and W model boiler tests: effect of temperature on IGA rate. Initial and post-1878 operating conditions of the model boilers

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    The Babcock and Wilcox (B and W) model boiler operated with 10 ppm weekly injections of NaOH for 41,900 hours (4.8 years). The model boiler operating conditions are given. Tube No. 24 failed by caustic intergranular attack/stress corrosion cracking (IGA/SCC) at the steam-water zone. IGA defect depths on tube 24 is compared at different locations, which also have different temperature conditions. The specific locations are: steam/water zone, drilled baffle plate, and lower tube sheet crevice. In all locations caustic will concentrate (although to different concentration levels). Nevertheless, an effect of temperature on IGA rate can be estimated. The degree of attack relative to the location and environment is shown. SEM fractographs illustrate the completely intergranular failure of Tube 24. A summary of the estimated results is presented. These results show the estimated IGA rate as a function of primary/secondary temperature and estimated caustic concentration. Details of the failure analysis of the model boiler can be found in the final report Destructive Examination of Babcock and Wilcox's Model Boiler for Intergranular Attack (IGA) on Tubes, EPRI S302-6, J.L.; Barna and L.W. Sarver

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

  7. FOULING ORGANISMS OF BUOYS WITHIN MAKHACHKALA SEAPORT

    Directory of Open Access Journals (Sweden)

    C. N. Imachova

    2011-01-01

    Full Text Available It is investigated biofouling buoys within Makhachkala seaport. Seasonal dynamics of development of community, structure species and trophic structure is revealed. It is established vertical zonality in distribution of fouling.

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

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  9. System for measuring the effect of fouling and corrosion on heat transfer under simulated OTEC conditions. [HTAU and LABTTF codes

    Energy Technology Data Exchange (ETDEWEB)

    Fetkovich, J.G.

    1976-12-01

    A complete system designed to measure, with high precision, changes in heat transfer rates due to fouling and corrosion of simulated heat exchanger tubes, at sea and under OTEC conditions is described. All aspects of the system are described in detail, including theory, mechanical design, electronics design, assembly procedures, test and calibration, operating procedures, laboratory results, field results, and data analysis programs.

  10. 30 CFR 77.413 - Boilers.

    Science.gov (United States)

    2010-07-01

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

  11. 30 CFR 56.13030 - Boilers.

    Science.gov (United States)

    2010-07-01

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

  12. 30 CFR 57.13030 - Boilers.

    Science.gov (United States)

    2010-07-01

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

  13. 29 CFR 1915.162 - Ship's boilers.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Ship's boilers. 1915.162 Section 1915.162 Labor Regulations... Ship's boilers. (a) Before work is performed in the fire, steam, or water spaces of a boiler where... dead boiler with the live system or systems shall be secured, blanked, and tagged indicating that...

  14. Fouling polyzoans of Bombay offshore waters

    Digital Repository Service at National Institute of Oceanography (India)

    Raveendran, T.V.; De; Wagh, A.B.

    (December), 1990, pp.169-178 FOULING POLYZOANS OF BOMBAY OFFSHORE WATERS T.V. RAVEENDRAN, A.P. DE SOUZA AND A.B. WAGH National InstituteofOceanography, Dona Paula, Goa-403 004. ABSTRACT Seven cheilostomatanand one cyclostornatan polyzoan observed as members... and Bhavanarayana, 1988 and De Souza, 1988) and there arehardly~nyreport from offshore regions. Thepresentpaperdeals with the fouling polyzoans from the offshore waters of Bombay High area; a station situated ap proximately 160 krn off Bombay. The watercolumnin...

  15. 46 CFR 61.05-10 - Boilers in service.

    Science.gov (United States)

    2010-10-01

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

  16. Fouling mechanism in ultrafiltration of vegetable oil

    Science.gov (United States)

    Ariono, D.; Wardani, A. K.; Widodo, S.; Aryanti, Putu T. P.; Wenten, I. G.

    2018-03-01

    Energy efficient and cost-effective separation of impurities from vegetable oil is a great challenge for vegetable oil processing. Several technologies have been developed, including pressurized membrane, chemical treatment, and chemical free separation methods. Among those technologies, ultrafiltration membrane is one of the most attractive processes with low operating pressure and temperature. In this work, hydrophobic polypropylene ultrafiltration membrane was used to remove impurities such as non-dissolved solids from palm kernel oil. Unfortunately, the hydrophobicity of polypropylene membrane leads to significant impact on the reduction of permeate flux due to membrane fouling. This fouling is associated with the accumulation of substances on the membrane surface or within the membrane pores. For better understanding, fouling mechanism that occurred during palm kernel oil ultrafiltration using hydrophobic polypropylene membrane was investigated. The effect of trans-membrane pressure and feed temperature on fouling mechanism was also studied. The result showed that cake formation became the dominant fouling mechanism up to 50 min operation of palm kernel oil ultrafiltration. Furthermore, the fouling mechanism was not affected by the increase of trans-membrane pressure and feed temperature.

  17. CFB boilers in multifuel application

    International Nuclear Information System (INIS)

    Goral, D.; Krzton, B.

    2007-01-01

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

  18. Increased algal fouling on mussels with barnacle epibionts: a fouling cascade

    Science.gov (United States)

    Gutiérrez, Jorge L.; Palomo, M. Gabriela

    2016-06-01

    If the external surfaces of epibionts are more suitable to other fouling species than those of their basibionts, a 'fouling cascade' might occur where epibionts facilitate secondary colonization by other epibionts. Here we evaluate whether the presence of epibiotic barnalces (Balanus glandula) influences the probability of mussel (Brachidontes rodriguezii) fouling by ephemeral red algae (Porphyra sp.) in a Southwestern Atlantic rocky shore. Mussels with barnacle epibionts showed a higher prevalence of Porphyra sp. fouling (32-40% depending on sampling date) than mussels without them (3-7%). Two lines of evidence indicate that barnacles facilitate Porphyra sp. fouling. First, most Porphyra sp. thalli in mussels with barnacle epibionts were attached to barnacle shells (75-92% of cases). Secondly, Porphyra sp. associated with mussels with barnacle epibionts in a proportion that significantly exceeded that expected under random co-occurrence. These results suggest the occurrence of a fouling cascade where barnacle epibiosis on mussels facilitates subsequent algal fouling. Recognizing the occurrence of such fouling cascades is important because they might explain the non-random aggregation of multiple epibiotic species onto a proportionally few individuals of the host species.

  19. 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 model...

  20. Hybrid model of steam boiler

    International Nuclear Information System (INIS)

    Rusinowski, Henryk; Stanek, Wojciech

    2010-01-01

    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.

  1. ENERGY STAR Certified Commercial Boilers

    Data.gov (United States)

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

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  3. 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.

  4. Condensing economizers for small coal-fired boilers and furnaces

    Energy Technology Data Exchange (ETDEWEB)

    Butcher, T.A.; Litzke, W.

    1994-01-01

    Condensing economizers increase the thermal efficiency of boilers by recovering sensible and latent heat from exhaust gas. These economizers are currently being used commercially for this purpose in a wide range of applications. Performance is dependent upon application-specific factors affecting the utility of recovered heat. With the addition of a condensing economizer boiler efficiency improvements up to 10% are possible. Condensing economizers can also capture flue gas particulates. In this work, the potential use of condensing economizers for both efficiency improvement and control of particulate emissions from small, coal water slurry-fired boilers was evaluated. Analysis was done to predict heat transfer and particulate capture by mechanisms including: inertial impaction, interception, diffusion, thermophoretic forces, and condensation growth. Shell-and-tube geometries were considered with flue gas on the outside of Teflon-covered tubes. Experimental studies were done with both air- and water-cooled economizers refit to a small boiler. Two experimental arrangements were used including oil-firing with injection of flyash upstream of the economizer and direct coal water slurry firing. Firing rates ranged from 27 to 82 kW (92,000 to 280,000 Btu/hr). Inertial impaction was found to be the most important particulate capture mechanism and removal efficiencies to 95% were achieved. With the addition of water sprays directly on the first row of tubes, removal efficiencies increased to 98%. Use of these sprays adversely affects heat recovery. Primary benefits of the sprays are seen to be the addition of small impaction sites and future design improvements are suggested in which such small impactors are permanently added to the highest velocity regions of the economizer. Predicted effects of these added impactors on particulate removal and pressure drop are presented.

  5. 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.

  6. Investigation of Filtration Membranes from the Dairy Protein Industry for Residual Fouling Using Infrared Spectroscopy and Chemometrics

    DEFF Research Database (Denmark)

    Jensen, Jannie Krog

    investigation (Paper I) describes the concentration development over the membrane leaves as a function of the distance from the feed inlet and the distance from the center permeate tube. A non-homogenous concentration distribution of residual fouling was observed with the highest concentration of residual...... the result showed that the MCR model needed three factors to describe the system, one describing the membrane material (polyethersulfone, PES), and two describing the residual fouling that is present on the membrane. The MCR method improved the interpretation of the models considerably compared to e.g. PCA...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-09-30

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

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

    International Nuclear Information System (INIS)

    Kim, Seongil; Choi, Sangmin

    2017-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-05-15

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

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

    International Nuclear Information System (INIS)

    Mathews, A.J.

    1988-01-01

    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)

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

    Science.gov (United States)

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

    2017-08-01

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

  12. Hydroelectric plant integrated with foul waters

    Science.gov (United States)

    Fragiacomo, P.; Scornaienchi, N. M.

    2005-09-01

    The foul water plant, the object of this work, involves the energy exploitation of the waters from two torrents and the foul water of a town in Southern Italy. The plant layout is such that it enables, moreover, the use of the same hydraulic works to supply irrigation water in the summer to farmers who work near the proposed mini-power station. With the aim of also carrying out an economic financial evaluation, the technical choices have been economically quantified and the outcome of these analyses have provided positive indications.

  13. Fuel characterization requirements for cofiring biomass in coal-fired boilers

    International Nuclear Information System (INIS)

    Prinzing, D.E.; Tillman, D.A.; Harding, N.S.

    1993-01-01

    The cofiring of biofuels with coal in existing boilers, or the cofiring of biofuels in combined cycle combustion turbine (CCCT) systems presents significant potential benefits to utilities, including reductions in SO 2 and NO x emissions as a function of reducing the mass flow of sulfur and nitrogen to the boiler, reducing CO 2 emissions from the combustion of fossil fuels; potentially reducing fuel costs both by the availability of wood residues and by the fact that biofuels are exempt from the proposed BTU tax; and providing support to industrial customers from the forest products industry. At the same time, cofiring requires careful attention to the characterization of the wood and coal, both singly and in combination. This paper reviews characterization requirements associated with cofiring biofuels and fossil fuels in boilers and CCCT installations with particular attention not only to such concerns as sulfur, nitrogen, moisture, and Btu content, but also to such issues as total ash content, base/acid ratio of the wood ash and the coal ash, alkali metal content in the wood ash and wood fuel (including converted fuels such as low Btu gas or pyrolytic oil), slagging and fouling indices, ash fusion temperature, and trace metal contents in the wood and coal. The importance of each parameter is reviewed, along with potential consequences of a failure to adequately characterize these parameters. The consequences of these parameters are reviewed with attention to firing biofuels with coal in pulverized coal (PC) and cyclone boilers, and firing biofuels with natural gas in CCCT installations

  14. Black liquor combustion validated recovery boiler modeling: Final year report. Volume 4 (Appendix IV)

    Energy Technology Data Exchange (ETDEWEB)

    Grace, T.M.; Frederick, W.J.; Salcudean, M.; Wessel, R.A.

    1998-08-01

    This project was initiated in October 1990, with the objective of developing and validating a new computer model of a recovery boiler furnace using a computational fluid dynamics (CFD) code specifically tailored to the requirements for solving recovery boiler flows, and using improved submodels for black liquor combustion based on continued laboratory fundamental studies. The key tasks to be accomplished were as follows: (1) Complete the development of enhanced furnace models that have the capability to accurately predict carryover, emissions behavior, dust concentrations, gas temperatures, and wall heat fluxes. (2) Validate the enhanced furnace models, so that users can have confidence in the predicted results. (3) Obtain fundamental information on aerosol formation, deposition, and hardening so as to develop the knowledge base needed to relate furnace model outputs to plugging and fouling in the convective sections of the boiler. (4) Facilitate the transfer of codes, black liquid submodels, and fundamental knowledge to the US kraft pulp industry. Volume 4 contains the following appendix sections: Radiative heat transfer properties for black liquor combustion -- Facilities and techniques and Spectral absorbance and emittance data; and Radiate heat transfer determination of the optical constants of ash samples from kraft recovery boilers -- Calculation procedure; Computation program; Density determination; Particle diameter determination; Optical constant data; and Uncertainty analysis.

  15. Investigation of Filtration Membranes from the Dairy Protein Industry for Residual Fouling Using Infrared Spectroscopy and Chemometrics

    DEFF Research Database (Denmark)

    Jensen, Jannie Krog

    Ultrafiltration and microfiltration operations are applied intensively in the dairy and water cleaning industries. The main capacity limiting factors of such operations are the flux and efficiency decline by irreversible adsorption of foulants onto the membranes and the efficiency by which...... the reversible fouling can be removed/cleaned. The aim of this thesis is to investigate the residual fouling that is deposited on ultrafiltration and microfiltration membranes after usage. The membrane surfaces are investigated using infrared spectroscopy with an attenuated reflectance sampling unit...... fouling present at the center tube decreasing in concentration outwards in a flame-like shape. The relative concentration calculations are based on the height of the amide II peak (1500-1550 cm-1) which was chosen because it unlike the amide I band has no interference with adsorbed water and other...

  16. 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.

  17. Superclean coal-water slurry combustion testing in an oil-fired boiler. Semiannual technical progress report, February 15, 1992--August 15, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Miller, B.G.; Pisupati, S.V.; Poe, R.L.; Morrison, J.L.; Xie, J.; Walsh, P.M.; Shamanna, S.; Schobert, H.H.; Scaroni, A.W.

    1992-10-13

    The Pennsylvania State University is conducting a superclean coal-water slurry (SCCWS) program for the United States Department of Energy (DOE) and the Commonwealth of Pennsylvania with the objective of determining the capability of effectively firing SCCWS in an industrial boiler designed for oil. Penn State has entered into a cooperative agreement with DOE to determine if SCCWS (a fuel containing coal with 3.0 wt.% ash and 0.9 wt.% sulfur) can effectively be burned in an oil-designed industrial boiler without adverse impact on boiler rating, maintainability, reliability, and availability. The project will provide information on the design of new systems specifically configured to fire these clean coal-based fuels. The project consists of four phases: (1) design, permitting, and test planning, (2) construction and start up, (3) demonstration and evaluation (1,000-hour demonstration), and (4) program expansion (additional 1,000 hours of testing). The boiler testing will determine if the SCCWS combustion characteristics, heat release rate, fouling and slagging behavior, corrosion and erosion limits, and fuel transport, storage, and handling characteristics can be accommodated in an oil-designed boiler system. In addition, the proof-of-concept demonstration will generate data to determine how the properties of SCCWS and its parent coal affect boiler performance. Economic factors associated with retrofitting and operating boilers will be identified to assess the viability of future oil-to-coal retrofits.

  18. Superclean coal-water slurry combustion testing in an oil-fired boiler. Semiannual technical progress report, August 15, 1992--February 15, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Miller, B.G.; Pisupati, S.V.; Poe, R.L.; Morrison, J.L.; Xie, J.; Walsh, P.M.; Wincek, R.T.; Clark, D.A.; Scaroni, A.W.

    1993-04-21

    The Pennsylvania State University is conducting a superclean coal-water slurry (SCCWS) program for the United States Department of Energy (DOE) and the Commonwealth of Pennsylvania with the objective of determining the capability of effectively firing SCCWS in an industrial boiler designed for heavy fuel oil. Penn State has entered into a cooperative agreement with DOE to determine if SCCWS (a fuel containing coal with 3.0 wt.% ash and 0.9 wt.% sulfur) can effectively be burned in a heavy fuel oil-designed industrial boiler without adverse impact on boiler rating, maintainability, reliability, and availability. The project will provide information on the design of new systems specifically configured to fire these clean coal-based fuels. The project consists of four phases: (1) design, permitting, and test planning, (2) construction and start up, (3) demonstration and evaluation (1,000-hour demonstration), and (4) program expansion (additional 1,000 hours of testing). The boiler testing wig determine if the SCCWS combustion characteristics, heat release rate, fouling and slagging behavior, corrosion and erosion limits, and fuel transport, storage, and handling characteristics can be accommodated in an oil-designed boiler system. In addition, the proof-of-concept demonstration will generate data to determine how the properties of SCCWS and its parent coal affect boiler performance. Economic factors associated with retrofitting boilers will be identified

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

    International Nuclear Information System (INIS)

    Diebel, M.E.

    1991-01-01

    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

  20. 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... required by § 56.95-10 of this subchapter and PW-41 of section I of the ASME Boiler and Pressure Vessel... section I of the ASME Boiler and Pressure Vessel Code may be provided. [CGFR 68-82, 33 FR 18815, Dec. 18...

  1. 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....... The CHP system may also be operated in a heating or cooling mode, thus being able to heat or cool water by feeding electricity to the system....

  2. CFD simulations of heat transfer in internally helically ribbed tubes

    Directory of Open Access Journals (Sweden)

    Majewski Karol

    2016-06-01

    Full Text Available Heating surfaces in power boilers are exposed to very high heat flux. For evaporator protection against overheating, internally helically ribbed tubes are used. The intensification of the heat transfer and the maintenance of the thin water layer in the intercostal space, using ribbed tubes, enables better protection of the power boiler evaporator than smooth pipes. Extended inner surface changes flow and thermal conditions by influencing the linear pressure drop and heat transfer coefficient. This paper presents equations that are used to determine the heat transfer coefficient. The results of total heat transfer, obtained from CFD simulations, for two types of internally ribbed and plain tubes are also presented.

  3. Heat transfer performance of condenser tubes in an MSF desalination system

    International Nuclear Information System (INIS)

    Galal, T.; Kalendar, A.; Al Saftawi, A.; Zedan, M.

    2010-01-01

    The present research examines the amount of condensed fresh water off the outer-side surface of heat exchangers in an MSF system. The quantitative modeling of condensed water on the outer surface of comparable tubes, enhanced and plain, in a simulated MSF technique is investigated. An adapted simulation design on a test-rig facility, accounting for the condenser tubing in actual industrial desalination plate-form, is used with corrugated and smooth aluminum-brass material tubes 1100mm long and 23mm bore. A single phase flow of authentic brine water that typifies real fouling is utilized to simulate the actual environmental life of a multi-stage flashing desalination system, with coolant flow velocity 0.1 m/s in the two delineated types of condenser tubing. It is demonstrated that the condensate water amount from the specified enhanced tube is about 1.22 times the condensate water amount from the smooth tube, adaptive for 140 running hours under deliberated constrains. The topic covers a comparative analysis of thermal performance. Comparing results with fresh water confirm the effect of fouling on significantly lowering the value of the overall heat transfer coefficient versus time. Fouling resistance R f is reported with the critical coolant flow speed of 0.1 m/s. Comparison between the fouling resistance for both smooth and corrugated tubes versus time is performed. The fouling thermal resistance of the corrugated tube is 0.56 of the fouling thermal resistance of the smooth tube after140 running hours of the experiment are concluded. Overall, in the case of real brine, results prove that heat performance for the corrugated tube is superior to the plain tube over the studied time period (140 hrs) for the chosen range of flow speeds

  4. Sootblowing optimization for improved boiler performance

    Science.gov (United States)

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

    2012-12-25

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

  5. SDI: Is it a reliable fouling index?

    NARCIS (Netherlands)

    Al-Hadidi, A.M.M.; Kemperman, Antonius J.B.; Schippers, J.C.; Wessling, Matthias; van der Meer, Walterus Gijsbertus Joseph

    2012-01-01

    The ASTM considers the silt density index (SDI) test as a standard test for fouling potential of RO and NF feed waters. Up to date, the SDI is used at many full- and pilot-scale installations. The design and choice of the applied RO pretreatment is to a large extent based on the SDI test on the raw

  6. Fouling in reverse electrodialysis under natural conditions

    NARCIS (Netherlands)

    Vermaas, David; Kunteng, Damnearn; Saakes, Michel; Nijmeijer, Dorothea C.

    2013-01-01

    Renewable energy can be generated from mixing salt water and fresh water in reverse electrodialysis. The potential for energy generation from mixing seawater and river water is enormous. To investigate the effect of fouling when such natural feed waters are used, the performance of three different

  7. Amphiphilic copolymers for fouling-release coatings

    DEFF Research Database (Denmark)

    Noguer, Albert Camós; Olsen, Stefan Møller; Hvilsted, Søren

    of the coatings [9,10,11]. This work shows the effect of an amphiphilic copolymer that induces hydrophilicity on the surface of the silicone-based fouling release coatings. The behaviour of these copolymers within the coating upon immersion and the interaction of these surface-active additives with other...

  8. Characterization of fouling of membrane contactors

    DEFF Research Database (Denmark)

    Ciurkot, Kaludia; Zarebska, Agata; Christensen, Knud Villy

    2013-01-01

    achieved higher ammonia removal than the synthetic model manure solution. This might be due to the larger particle size of the milled straw in the model solution compared to the size of suspended solids present in real manure. From the fouling autopsy, it was found that PTFE membranes are more prone...

  9. Fouling corrosion in aluminum heat exchangers

    Directory of Open Access Journals (Sweden)

    Su Jingxin

    2015-06-01

    Full Text Available Fouling deposits on aluminum heat exchanger reduce the heat transfer efficiency and cause corrosion to the apparatus. This study focuses on the corrosive behavior of aluminum coupons covered with a layer of artificial fouling in a humid atmosphere by their weight loss, Tafel plots, electrochemical impedance spectroscopy (EIS, and scanning electron microscope (SEM observations. The results reveal that chloride is one of the major elements found in the fouling which damages the passive film and initiates corrosion. The galvanic corrosion between the metal and the adjacent carbon particles accelerates the corrosive process. Furthermore, the black carbon favors the moisture uptake, and gives the dissolved oxygen greater chance to migrate through the fouling layer and form a continuous diffusive path. The corrosion rate decreasing over time is conformed to electrochemistry measurements and can be verified by Faraday’s law. The EIS results indicate that the mechanism of corrosion can be interpreted by the pitting corrosion evolution mechanism, and that pitting was observed on the coupons by SEM after corrosive exposure.

  10. Site radiography in boiler industry

    International Nuclear Information System (INIS)

    Hemachandran, P.

    1977-01-01

    Isotope radiography enjoys a unique position in radiography of weldments made at erection sites of industrial boilers. It also faces problems due to unfavourable conditions existing in these sites. The over-all approach to radiography at boiler erection sites has been dealt with. The advantages of modern X-ray and gamma ray equipment for these particular applications are discussed. A few useful accessories which reduce the complexity of source positioning and allied problems due to elevated position are suggested. Safety problems at sites are also dealt with. (author)

  11. The Modified Fouling Index Ultrafiltration constant flux for assessing particulate/colloidal fouling of RO systems

    KAUST Repository

    Salinas-Rodriguez, Sergio G.

    2015-02-18

    Reliable methods for measuring and predicting the fouling potential of reverse osmosis (RO) feed water are important in preventing and diagnosing fouling at the design stage, and for monitoring pre-treatment performance during plant operation. The Modified Fouling Index Ultrafiltration (MFI-UF) constant flux is a significant development with respect to assessing the fouling potential of RO feed water. This research investigates (1) the variables influencing the MFI-UF test at constant flux filtration (membrane pore size, membrane material, flux rate); and (2) the application of MFI-UF into pre-treatment assessment and RO fouling estimation. The dependency of MFI on flux, means that to assess accurately particulate fouling in RO systems, the MFI should be measured at a flux similar to a RO system (close to 20 L/m2/h) or extrapolated from higher fluxes. The two studied membrane materials showed reproducible results; 10% for PES membranes and 6.3% for RC membranes. Deposition factors (amount of particles that remain on the surface of membrane) were measured in a full-scale plant ranging between 0.2 and 0.5. The concept of “safe MFI” is presented as a guideline for assessing pre-treatment for RO systems.

  12. Mitigation of Syngas Cooler Plugging and Fouling

    Energy Technology Data Exchange (ETDEWEB)

    Bockelie, Michael J. [Reaction Engineering International, Salt Lake City, UT (United States)

    2015-06-29

    This Final Report summarizes research performed to develop a technology to mitigate the plugging and fouling that occurs in the syngas cooler used in many Integrated Gasification Combined Cycle (IGCC) plants. The syngas cooler is a firetube heat exchanger located downstream of the gasifier. It offers high thermal efficiency, but its’ reliability has generally been lower than other process equipment in the gasification island. The buildup of ash deposits that form on the fireside surfaces in the syngas cooler (i.e., fouling) lead to reduced equipment life and increased maintenance costs. Our approach to address this problem is that fouling of the syngas cooler cannot be eliminated, but it can be better managed. The research program was funded by DOE using two budget periods: Budget Period 1 (BP1) and Budget Period 2 (BP2). The project used a combination of laboratory scale experiments, analysis of syngas cooler deposits, modeling and guidance from industry to develop a better understanding of fouling mechanisms and to develop and evaluate strategies to mitigate syngas cooler fouling and thereby improve syngas cooler performance. The work effort in BP 1 and BP 2 focused on developing a better understanding of the mechanisms that lead to syngas cooler plugging and fouling and investigating promising concepts to mitigate syngas cooler plugging and fouling. The work effort focused on the following: • analysis of syngas cooler deposits and fuels provided by an IGCC plant collaborating with this project; • performing Jet cleaning tests in the University of Utah Laminar Entrained Flow Reactor to determine the bond strength between an ash deposit to a metal plate, as well as implementing planned equipment modifications to the University of Utah Laminar Entrained Flow Reactor and the one ton per day, pressurized Pilot Scale Gasifier; • performing Computational Fluid Dynamic modeling of industrially relevant syngas cooler configurations to develop a better

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-06-30

    in a pilot scale furnace and soot behavior predicted by the CFD model showed good agreement. Field and laboratory tests were performed for SCR catalysts used for coal and biomass co-firing applications. Fundamental laboratory studies were performed to better understand mechanisms involved with catalyst deactivation. Field tests with a slip stream reactor were used to create catalyst exposed to boiler flue gas for firing coal and for co-firing coal and biomass. The field data suggests the mechanisms leading to catalyst deactivation are, in order of importance, channel plugging, surface fouling, pore plugging and poisoning. Investigations were performed to better understand the mechanisms involved with catalyst regeneration through mechanical or chemical methods. A computer model was developed to predict NOx reduction across the catalyst in a SCR. Experiments were performed to investigate the fundamentals of ammonia/fly ash interactions with relevance to the operation of advanced NOx control technologies such as selective catalytic reduction. Measurements were performed for 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. This work resulted in the first fundamental ammonia isotherms on carbon-containing fly ash samples. This work confirms industrial reports that aqueous solution chemistry takes place upon the introduction of even very small amounts of water, while the ash remains in a semi-dry state.

  14. Measurements of absorbed heat flux and water-side heat transfer coefficient in water wall tubes

    Science.gov (United States)

    Taler, Jan; Taler, Dawid; Kowal, Andrzej

    2011-04-01

    The tubular type instrument (flux tube) was developed to identify boundary conditions in water wall tubes of steam boilers. The meter is constructed from a short length of eccentric tube containing four thermocouples on the fire side below the inner and outer surfaces of the tube. The fifth thermocouple is located at the rear of the tube on the casing side of the water-wall tube. The boundary conditions on the outer and inner surfaces of the water flux-tube are determined based on temperature measurements at the interior locations. Four K-type sheathed thermocouples of 1 mm in diameter, are inserted into holes, which are parallel to the tube axis. The non-linear least squares problem is solved numerically using the Levenberg-Marquardt method. The heat transfer conditions in adjacent boiler tubes have no impact on the temperature distribution in the flux tubes.

  15. Novel graphical approach as fouling pinch for increasing fouling formation period in heat exchanger network (HEN) state of the art

    International Nuclear Information System (INIS)

    Azad, Abazar Vahdat; Ghaebi, Hadi; Amidpour, Majid

    2011-01-01

    In this paper a new graphical tool is proposed for investigation of fouling formation period in heat exchanger networks (HEN). The objective of this paper is increasing the time that HEN can perform its desirable heat transfer operation without required cleaning process. In a typical heat exchanger network, fouling formation rate of some streams is more than other ones. The method obtained in this work is based on given more opportunity for fouling formation for streams with high fouling formation rate. In fact high fouling formation rate streams are replaced with low fouling formation rate streams between different heat exchangers so that more fouling formation opportunity may be given for HEN. Therefore the HEN cleaning time decreases in fixed time period and the high fouling formation streams should pass from the path that the low fouling formation rate stream previously has passed, and inversely. As a result, secondly stream with high fouling formation rate mixes with residues of primary stream (low fouling formation rate stream). Therefore we should consider to adoption and conformability of streams structures (for prevention of streams destruction) and thermal considerations (for desirable heat transfer). Outlet temperatures of hot and cold streams should state in predefined temperatures. For satisfying thermal consideration after streams replacement this approach can be used in plants that cleanliness and its operational costs are most important problem.

  16. The effect of the removal of steam generator tube ID deposits of heat transfer

    International Nuclear Information System (INIS)

    Klimas, S.J.; Miller, D.G.; Semmler, J.; Turner, C.W.

    1998-12-01

    The thermal resistance of boiler primary-side tube deposits from the Gentilly-2 Nuclear Generating Station (Hydro-Quebec) was evaluated by an experimental comparison of the heat-transfer rates between fouled samples and identical, factory-new, 'clean' tubing. The deposits were subsequently removed using either a chemical decontamination process (CAN-DEREM Plus) or a mechanical cleaning process (Siemens SIVABLAST) in two stages. After each removal, the thermal resistance of the remaining deposit was remeasured. The 90- to 150-μm-thick deposits on the inside diameter of steam generator cold-leg tubes were found to pose significant resistance to heat transfer (0.05 to 0.06 m 2 ·K/kW at 210 degrees C). However, the 10- to 30-μm-thick dense layers remaining on the tubes after the decontamination were found to have no measurable effect on the heat transfer. The thin, 2-μm tube deposit on the steam generator hot leg slightly enhanced heat transfer. The measured thermal resistance results in a calculated thermal conductivity of 1.5 W/m·K for the 90-μm-thick deposit. The 150-μm-thick deposits were found to consist of two layers: an outer surface layer having an average porosity of 50% and a conductivity of 2.3 W/m·K, and an inner layer having an average porosity of 5% and a conductivity of >3.0 W/m·K. The previous best estimate of the thermal conductivity was 1.4 W/m.K for the porous magnetite deposits that had formed with a thickness <90 μm on the primary side of nuclear steam generators. This work confirms this number, but also demonstrates that it is applicable only for porous, unconsolidated deposits. The conductivity increases for thicker deposits because of increasing deposit consolidation, particularly at the innermost layer adjacent to the tube metal. (author)

  17. The effect of the removal of steam generator tube ID deposits of heat transfer

    Energy Technology Data Exchange (ETDEWEB)

    Klimas, S.J.; Miller, D.G.; Semmler, J.; Turner, C.W

    1998-12-01

    The thermal resistance of boiler primary-side tube deposits from the Gentilly-2 Nuclear Generating Station (Hydro-Quebec) was evaluated by an experimental comparison of the heat-transfer rates between fouled samples and identical, factory-new, 'clean' tubing. The deposits were subsequently removed using either a chemical decontamination process (CAN-DEREM Plus) or a mechanical cleaning process (Siemens SIVABLAST) in two stages. After each removal, the thermal resistance of the remaining deposit was remeasured. The 90- to 150-{mu}m-thick deposits on the inside diameter of steam generator cold-leg tubes were found to pose significant resistance to heat transfer (0.05 to 0.06 m{sup 2}{center_dot}K/kW at 210 degrees C). However, the 10- to 30-{mu}m-thick dense layers remaining on the tubes after the decontamination were found to have no measurable effect on the heat transfer. The thin, 2-{mu}m tube deposit on the steam generator hot leg slightly enhanced heat transfer. The measured thermal resistance results in a calculated thermal conductivity of 1.5 W/m{center_dot}K for the 90-{mu}m-thick deposit. The 150-{mu}m-thick deposits were found to consist of two layers: an outer surface layer having an average porosity of 50% and a conductivity of 2.3 W/m{center_dot}K, and an inner layer having an average porosity of 5% and a conductivity of >3.0 W/m{center_dot}K. The previous best estimate of the thermal conductivity was 1.4 W/m.K for the porous magnetite deposits that had formed with a thickness <90 {mu}m on the primary side of nuclear steam generators. This work confirms this number, but also demonstrates that it is applicable only for porous, unconsolidated deposits. The conductivity increases for thicker deposits because of increasing deposit consolidation, particularly at the innermost layer adjacent to the tube metal. (author)

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

    International Nuclear Information System (INIS)

    Liu, Xingrang; Bansal, R.C.

    2014-01-01

    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

  19. Installations of SNCR on bark-fired boilers; Uppfoeljning av SNCR-installationer paa barkpannor

    Energy Technology Data Exchange (ETDEWEB)

    Hjalmarsson, A.K.; Hedin, K. [AaF-Energikonsult, Stockholm (Sweden); Andersson, Lars [AaF-IPK (Sweden)

    1997-01-01

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

  20. A numerical study on thermal behavior of a D-type water-cooled steam boiler

    International Nuclear Information System (INIS)

    Moghari, M.; Hosseini, S.; Shokouhmand, H.; Sharifi, H.; Izadpanah, S.

    2012-01-01

    To achieve a precise assessment on thermal performance of a D-type water-cooled natural gas-fired boiler the present paper was aimed at determining temperature distribution of water and flue gas flows in its different heat exchange equipment. Using the zonal method to predict thermal radiation treatment in the boiler furnace and a numerical iterative approach, in which heat and fluid flow relations associated with different heat surfaces in the boiler convective zone were employed to estimate heat transfer characteristics, enabled this numerical study to obtain results in good agreement with experimental data measured in the utility site during steady state operation. A constant flow rate for a natural gas fuel of specified chemical composition was assumed to be mixed with a given excess ratio of air flow at a full boiler load. Significant results attributed to distribution of heat flux on different furnace walls and that of flue gas and water/steam temperature in different convective stages including superheater, evaporating risers and downcomers modules, and economizer were obtained. Besides the rate of heat absorption in every stage and other essential parameters in the boiler design too, inherent thermal characteristics like radiative and convective heat transfer coefficients as well as overall heat transfer conductance and effectiveness of convective stages considered as cross-flow heat exchangers were eventually presented for the given operating condition. - Highlights: ► Detailed distribution of heat flux on all of the boiler furnace walls was obtained. ► Flue gas and water thermal behaviors in different heating sections were evaluated. ► A good agreement was made between numerical results and experimental data. ► Contribution of the boiler furnace to the total thermal absorption was 39%. ► Contribution of the boiler tube banks to the total thermal absorption was 61%.

  1. Biomass boiler still best choice

    International Nuclear Information System (INIS)

    Wallace, Paula

    2014-01-01

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

  2. 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

    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...

  3. Fouling resistance prediction using artificial neural network nonlinear auto-regressive with exogenous input model based on operating conditions and fluid properties correlations

    Energy Technology Data Exchange (ETDEWEB)

    Biyanto, Totok R. [Department of Engineering Physics, Institute Technology of Sepuluh Nopember Surabaya, Surabaya, Indonesia 60111 (Indonesia)

    2016-06-03

    Fouling in a heat exchanger in Crude Preheat Train (CPT) refinery is an unsolved problem that reduces the plant efficiency, increases fuel consumption and CO{sub 2} emission. The fouling resistance behavior is very complex. It is difficult to develop a model using first principle equation to predict the fouling resistance due to different operating conditions and different crude blends. In this paper, Artificial Neural Networks (ANN) MultiLayer Perceptron (MLP) with input structure using Nonlinear Auto-Regressive with eXogenous (NARX) is utilized to build the fouling resistance model in shell and tube heat exchanger (STHX). The input data of the model are flow rates and temperatures of the streams of the heat exchanger, physical properties of product and crude blend data. This model serves as a predicting tool to optimize operating conditions and preventive maintenance of STHX. The results show that the model can capture the complexity of fouling characteristics in heat exchanger due to thermodynamic conditions and variations in crude oil properties (blends). It was found that the Root Mean Square Error (RMSE) are suitable to capture the nonlinearity and complexity of the STHX fouling resistance during phases of training and validation.

  4. Diesel injector fouling bench test methodology

    Science.gov (United States)

    Stavinoha, Leon L.; Yost, Douglas M.; Lestz, Sidney J.

    1992-06-01

    Compared to conventional compression ignition (CI) engine operation with the fuel being delivered at approximately 149 C (300 F), adiabatic engine operation potentially may deliver the fuel at temperatures as high as 260 C (500 F). Hypergolic CI engine combustion systems now in theoretical design stages will deliver fuel at temperatures approaching 427 to 538 C (800 to 1000 F). The ability of a fuel to resist formation of deposits on internal injector system surfaces is a form of thermal oxidative stability for which test methodology will be required. The injector Fouling Bench Test (IFBT) methodology evaluated in this report will assist in defining fuel contribution to injector fouling and control of fuel thermal stability in procurement specifications. The major observations from this project are discussed. Forty-hour cyclic IFB tests employing both Bosch APE 113 and Detroit Diesel (DD) N70 injectors are viable procedures for evaluating fuel effects on injector fouling. Cyclic operation appears to be superior to steady-state operation for both type injectors. Eighty-hour cyclic tests are more discriminating than 40-hour cyclic tests using the Bosch APE 113 injectors. JFTOT tests of fuels provide directional information on thermal stability-related deposits and filter plugging but show limited good correlation with IFBT DD N70 ratings, and none with IFBT Bosch APE 113 injector ratings. Deposition on injector pintles was more realistically rated by optical microscopy and Scanning Electron Microscopy (SEM) than conventional visual and bench rating methods. High-sulfur fuel readily caused sticking of Detroit Diesel injectors. Injector sticking is an important mode of injector fouling.

  5. Coke fouling monitoring by electrical resistivity

    Energy Technology Data Exchange (ETDEWEB)

    Bombardelli, Clovis; Mari, Livia Assis; Kalinowski, Hypolito Jose [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil). Programa de Pos-Graduacao em Engenharia Eletrica e Informatica Industrial (CPGEI)

    2008-07-01

    An experimental method to simulate the growth of the coke fouling that occurs in the oil processing is proposed relating the thickness of the encrusted coke to its electrical resistivity. The authors suggest the use of the fouling electrical resistivity as a transducer element for determining its thickness. The sensor is basically two electrodes in an electrically isolated device where the inlay can happen in order to compose a purely resistive transducer. Such devices can be easily constructed in a simple and robust form with features capable to face the high temperatures and pressures found in relevant industrial processes. For validation, however, it is needed a relationship between the electrical resistivity and the fouling thickness, information not yet found in the literature. The present work experimentally simulates the growth of a layer of coke on an electrically insulating surface, equipped with electrodes at two extremities to measure the electrical resistivity during thermal cracking essays. The method is realized with a series of consecutive runs. The results correlate the mass of coke deposited and its electrical resistivity, and it can be used to validate the coke depositions monitoring employing the resistivity as a control parameter. (author)

  6. 46 CFR 52.25-20 - Exhaust gas boilers.

    Science.gov (United States)

    2010-10-01

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

  7. 46 CFR 63.25-1 - Small automatic auxiliary boilers.

    Science.gov (United States)

    2010-10-01

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

  8. A comprehensive review of milk fouling on heated surfaces.

    Science.gov (United States)

    Sadeghinezhad, E; Kazi, S N; Dahari, M; Safaei, Mohammad Reza; Sadri, Rad; Badarudin, A

    2015-01-01

    Heat exchanger performance degrades rapidly during operation due to formation of deposits on heat transfer surfaces which ultimately reduces service life of the equipment. Due to scaling, product deteriorates which causes lack of proper heating. Chemistry of milk scaling is qualitatively understood and the mathematical models for fouling at low temperatures have been produced but the behavior of systems at ultra high temperature processing has to be studied further to understand in depth. In diversified field, the effect of whey protein fouling along with pressure drop in heat exchangers were conducted by many researchers. Adding additives, treatment of heat exchanger surfaces and changing of heat exchanger configurations are notable areas of investigation in milk fouling. The present review highlighted information about previous work on fouling, influencing parameters of fouling and its mitigation approach and ends up with recommendations for retardation of milk fouling and necessary measures to perform the task.

  9. Identification of Material Parameters for the Simulation of Acoustic Absorption of Fouled Sintered Fiber Felts

    Directory of Open Access Journals (Sweden)

    Nicolas Lippitz

    2016-08-01

    Full Text Available As a reaction to the increasing noise pollution, caused by the expansion of airports close to residential areas, porous trailing edges are investigated to reduce the aeroacoustic noise produced by flow around the airframe. Besides mechanical and acoustical investigations of porous materials, the fouling behavior of promising materials is an important aspect to estimate the performance in long-term use. For this study, two sintered fiber felts were selected for a long-term fouling experiment where the development of the flow resistivity and accumulation of dirt was observed. Based on 3D structural characterizations obtained from X-ray tomography of the initial materials, acoustic models (Biot and Johnson–Champoux–Allard in the frame of the transfer matrix method were applied to the sintered fiber felts. Flow resistivity measurements and the measurements of the absorption coefficient in an impedance tube are the basis for a fouling model for sintered fiber felts. The contribution will conclude with recommendations concerning the modeling of pollution processes of porous materials.

  10. Oxygen pitting failure of a bagasse boiler tube

    CSIR Research Space (South Africa)

    Heyes, AM

    2001-04-01

    Full Text Available that the pitting occurred during an idle period (a drought) due to oxygen ingress and failure to maintain a sufficient excess of the oxygen scavenger, sodium sulphite. The transverse orientation of the cracks and other factors suggest that the fatigue cracking...

  11. 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)

  12. Fouling in Membrane Distillation, Osmotic Distillation and Osmotic Membrane Distillation

    Directory of Open Access Journals (Sweden)

    Mourad Laqbaqbi

    2017-03-01

    Full Text Available Various membrane separation processes are being used for seawater desalination and treatment of wastewaters in order to deal with the worldwide water shortage problem. Different types of membranes of distinct morphologies, structures and physico-chemical characteristics are employed. Among the considered membrane technologies, membrane distillation (MD, osmotic distillation (OD and osmotic membrane distillation (OMD use porous and hydrophobic membranes for production of distilled water and/or concentration of wastewaters for recovery and recycling of valuable compounds. However, the efficiency of these technologies is hampered by fouling phenomena. This refers to the accumulation of organic/inorganic deposits including biological matter on the membrane surface and/or in the membrane pores. Fouling in MD, OD and OMD differs from that observed in electric and pressure-driven membrane processes such electrodialysis (ED, membrane capacitive deionization (MCD, reverse osmosis (RO, nanofiltration (NF, ultrafiltration (UF, microfiltration (MF, etc. Other than pore blockage, fouling in MD, OD and OMD increases the risk of membrane pores wetting and reduces therefore the quantity and quality of the produced water or the concentration efficiency of the process. This review deals with the observed fouling phenomena in MD, OD and OMD. It highlights different detected fouling types (organic fouling, inorganic fouling and biofouling, fouling characterization techniques as well as various methods of fouling reduction including pretreatment, membrane modification, membrane cleaning and antiscalants application.

  13. Feeding Tubes

    Science.gov (United States)

    ... the TPN. Tubes Used for Enteral Feeds NG (Nasogastric Tube) A flexible tube is placed via the nose, ... portion of the small intestine Naso – nose NG – Nasogastric Tube -ostomy – new opening Percutaneous – through the skin PEJ – ...

  14. A two-parameter preliminary optimization study for a fluidized-bed boiler through a comprehensive mathematical simulator

    Energy Technology Data Exchange (ETDEWEB)

    Rabi, Jose A.; Souza-Santos, Marcio L. de [Universidade Estadual de Campinas, SP (Brazil). Faculdade de Engenharia Mecanica. Dept. de Energia]. E-mails: jrabi@fem.unicamp.br; dss@fem.unicamp.br

    2000-07-01

    Modeling and simulation of fluidized-bed equipment have demonstrated their importance as a tool for design and optimization of industrial equipment. Accordingly, this work carries on an optimization study of a fluidized-bed boiler with the aid of a comprehensive mathematical simulator. The configuration data of the boiler are based on a particular Babcock and Wilcox Co. (USA) test unit. Due to their importance, the number of tubes in the bed section and the air excess are chosen as the parameters upon which the optimization study is based. On their turn, the fixed-carbon conversion factor and the boiler efficiency are chosen as two distinct optimization objectives. The results from both preliminary searches are compared. The present work is intended to be just a study on possible routes for future optimization of larger boilers. Nonetheless, the present discussion might give some insight on the equipment behavior. (author)

  15. 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.

  16. CFD analysis of temperature imbalance in superheater/reheater region of tangentially coal-fired boiler

    Science.gov (United States)

    Zainudin, A. F.; Hasini, H.; Fadhil, S. S. A.

    2017-10-01

    This paper presents a CFD analysis of the flow, velocity and temperature distribution in a 700 MW tangentially coal-fired boiler operating in Malaysia. The main objective of the analysis is to gain insights on the occurrences in the boiler so as to understand the inherent steam temperature imbalance problem. The results show that the root cause of the problem comes from the residual swirl in the horizontal pass. The deflection of the residual swirl due to the sudden reduction and expansion of the flow cross-sectional area causes velocity deviation between the left and right side of the boiler. This consequently results in flue gas temperature imbalance which has often caused tube leaks in the superheater/reheater region. Therefore, eliminating the residual swirl or restraining it from being diverted might help to alleviate the problem.

  17. Boiler plants completed in record time

    International Nuclear Information System (INIS)

    Anon.

    2001-01-01

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

  18. 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...

  19. Hydraulically irreversible fouling on ceramic MF/UF membranes: comparison of fouling indices, foulant composition and irreversible pore narrowing

    KAUST Repository

    Shang, Ran

    2015-05-06

    The application of ceramic membranes in water treatment is becoming increasing attractive because of their long life time and excellent chemical, mechanical and thermal stability. However, fouling of ceramic membranes, especially hydraulically irreversible fouling, is still a critical aspect affecting the operational cost and energy consumption in water treatment plants. In this study, four ceramic membranes with pore sizes or molecular weight cut-off (MWCO) of 0.20 μm, 0.14 μm, 300 kDa and 50 kDa were compared during natural surface water filtration with respect to hydraulically irreversible fouling index (HIFI), foulant composition and narrowing of pore size due to the irreversible fouling. Our results showed that the hydraulically irreversible fouling index (HIFI) was proportional to the membrane pore size (r2=0.89) when the same feed water was filtrated. The UF membranes showed lower HIFI values than the MF membranes. Pore narrowing (internal fouling) was found to be a main fouling pattern of the hydraulically irreversible fouling. The internal fouling was caused by monolayer adsorption of foulants with different sizes that is dependent on the size of the membrane pore.

  20. Coal-water slurry fuel combustion testing in an oil-fired industrial boiler. Semiannual technical progress report, August 15, 1994--February 15, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Miller, B.G.

    1995-05-12

    The Pennsylvania State University is conducting a coal-water slurry fuel (CWSF) program for the United States Department of Energy (DOE) and the Commonwealth of Pennsylvania with the objective of determining the viability of firing CWSF in an industrial boiler designed for heavy fuel oil. Penn State and DOE have entered into a cooperative agreement to determine if CWSFs prepared from cleaned coal (containing approximately 3.5 wt.% ash and 0.9 wt.% sulfur) can be burned effectively in a heavy fuel oil-designed industrial boiler without adverse impact on boiler rating, maintainability, reliability, and availability. The project will also provide information to help in the design of new systems specifically configured to fire these clean coal-based fuels. The project consists of four phases: (1) design, permitting, and test planning, (2) construction and start up, (3) demonstration and evaluation (1,000-hour demonstration), and (4) expanded demonstration and evaluation (installing a CWSF preparation circuit, conducting an additional 1,000 hours of testing, and installing an advanced flue gas treatment system). The boiler testing and evaluation will determine if the CWSF combustion characteristics, heat release rate, fouling and stagging behavior, corrosion and erosion tendencies, and fuel transport, storage, and handling characteristics can be accommodated in a boiler system designed to fire heavy fuel oil. In addition, the proof-of-concept demonstration will generate data to determine how the properties of a CWSF and its parent coal affect boiler performance. The economic factors associated with retrofitting boilers will also be evaluated. The first three phases (i.e., the first demonstration) have been completed and the combustion performance of the burner that was provided with the boiler did not meet performance goals. Consequently, the first demonstration has been concluded at 500 hours.

  1. Study of the possibility of thermal utilization of contaminated water in low-power boilers

    Science.gov (United States)

    Roslyakov, P. V.; Proskurin, Y. V.; Zaichenko, M. N.

    2017-09-01

    The utilization of water contaminated with oil products is a topical problem for thermal power plants and boiler houses. It is reasonable to use special water treatment equipment only for large power engineering and industry facilities. Thermal utilization of contaminated water in boiler furnaces is proposed as an alternative version of its utilization. Since there are hot-water fire-tube boilers at many enterprises, it is necessary to study the possibility of thermal utilization of water contaminated with oil products in their furnaces. The object of this study is a KV-GM-2.0 boiler with a heating power of 2 MW. The pressurized burner developed at the Moscow Power Engineering Institute, National Research University, was used as a burner device for supplying liquid fuel. The computational investigations were performed on the basis of the computer simulation of processes of liquid fuel atomization, mixing, ignition, and burnout; in addition, the formation of nitrogen oxides was simulated on the basis of ANSYS Fluent computational dynamics software packages, taking into account radiative and convective heat transfer. Analysis of the results of numerical experiments on the combined supply of crude oil and water contaminated with oil products has shown that the thermal utilization of contaminated water in fire-tube boilers cannot be recommended. The main causes here are the impingement of oil droplets on the walls of the flame tube, as well as the delay in combustion and increased emissions of nitrogen oxides. The thermal utilization of contaminated water combined with diesel fuel can be arranged provided that the water consumption is not more than 3%; however, this increases the emission of nitrogen oxides. The further increase in contaminated water consumption will lead to the reduction of the reliability of the combustion process.

  2. Polymeric dispersants for control of steam generator fouling

    Energy Technology Data Exchange (ETDEWEB)

    Balakrishnan, P.V.; Klimas, S.J. [Atomic Energy of Canada Limited, Chalk River, Ontario (Canada); Lepine, L. [Institut de Recherche d' Hydro-Quebec, Varennes, Quebec (Canada); Turner, C.W

    1999-05-01

    Fouling of steam generators by corrosion products from the feedtrain leads to loss of heat-transfer efficiency, disturbances in thermalhydraulics, and potential corrosion problems resulting from the development of sites for localized accumulation of aggressive chemicals. This report summarizes studies of the use of polymeric dispersants for the control of fouling, which were conducted at the Chalk River Laboratories. High-temperaturesettling studies on magnetite suspensions were performed to screen available generic dispersants, and the dispersants were ranked in terms of their dispersion efficiency; polyacrylic acid (PAA) and the phosphonate, HEDP, were ranked as the most efficient. Polyacrylic acid was considered more suitable than HEDP for nuclear steam generators, and more emphasis was given to the former in these studies. The dispersants had no effect on the particle deposition rates under single-phase forced-convective flow, but did reduce the deposition rates under flow-boiling conditions. The extent to which the deposition rates were reduced increased in proportion to the dispersant concentration. Preliminary corrosion tests indicated that pitting or general corrosion of steam generator tube materials in the presence of PAA was negligible. Corrosion of carbon steel, although higher in a magnetite-packed crevice under heat flux than in bulk water, was lower in the presence of PAA than in its absence. Some impurities (e.g., sulphate, sodium) were observed in commercially available PAA products at small, though significant concentrations, making these products unacceptable for use in nuclear plants. However, the PAA could be purified by ion exchange. Preliminary experiments, to assess the thermal stability of PAA at steam generator operating temperature, showed the polymer to break down in deaerated solutions and under argon cover to give hydrogen and carbon dioxide as the two major products in the gas phase and variable concentrations of acetate and formate

  3. Minimum gas speed in heat exchangers to avoid particulate fouling

    NARCIS (Netherlands)

    Abd-Elhady, M.S.; Rindt, C.C.M.; Wijers, J.G.; van Steenhoven, A.A.; Bramer, Eduard A.; van der Meer, Theodorus H.

    2004-01-01

    The minimum gas speed for a heat exchanger (HE) at which particulate fouling is avoided is investigated. Fouling experiments have been done with particles of different sizes and different materials running under different gas speeds. It is found that the smallest particles in the flow deposit first

  4. Fouling detection in heat exchangers by Takagi-Sugeno observers

    International Nuclear Information System (INIS)

    Delrot, Sabrina

    2012-01-01

    The phenomenon of fouling in heat exchangers is currently an important topic. Indeed, the fouling is a costly issue that increases the energy loss (directly or indirectly through an over-sizing of the equipment), and therefore increases the water consumption. As a side effect, fouling increases CO 2 consumption that leads to environmental consequences. Fouling can be detected either on local scale, using expensive and specific sensors or on global scale. Global estimation of fouling can be done by measuring the variation of the mass of the exchanger, or by estimating the efficiency of the exchanger through the transfer coefficient. These two methods require very restricting conditions: a powered exchanger to measure mass variation and a steady state exchanger to estimate the efficiency. The work introduced in this thesis deals with the development of non-linear observers that detect fouling early enough to start an efficient cleaning process. As a beginning, a finite element model of a counter current tubular exchanger was proposed. Then three approaches, based on non-linear Takagi-Sugeno observers, were suggested to detect early fouling in heat exchangers. First approach consisted in a set of observers that estimated the parameters of fouling effect through an interpolation method. The second approach proposed a polynomial Takagi-Sugeno observer, using the theory of sums of squares. Finally, a observer of Takagi-Sugeno type with unknown inputs was developed. As a conclusion, a comparison between those different methods was done. (author)

  5. Fouling layer characterization and pore-blocking mechanisms in an ...

    African Journals Online (AJOL)

    A pilot-scale UASB reactor coupled with an external ultrafiltration (UF) membrane was operated under three different hydraulic retention times (HRT: 4, 8 and 12 h) for municipal wastewater treatment in order to assess the composition and distribution of the fouling layer, as well as to identify the predominant fouling ...

  6. Real time visual characterization of membrane fouling and cleaning

    NARCIS (Netherlands)

    Ngene, I.S.

    2010-01-01

    The research presented in this thesis is focused on the phenomena of membrane fouling. Membrane fouling is simply described as the deposition of unwanted matter on the membrane surface during the course of operation, which results in reduction in filtration efficiency. This research is aimed at

  7. 46 CFR 109.555 - Propulsion boilers.

    Science.gov (United States)

    2010-10-01

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

  8. Review: Factors affecting fouling in conventional pens for slaughter pigs

    DEFF Research Database (Denmark)

    Larsen, Mona Lilian Vestbjerg; Bertelsen, Maja; Pedersen, Lene Juul

    2018-01-01

    This review assesses factors affecting fouling in conventional pens for slaughter pigs. Fouling of the pen happens when pigs change their excretory behaviour from occurring in the designated dunging area to the lying area. This can result in a lower hygiene, bad air quality, extra work for the fa......This review assesses factors affecting fouling in conventional pens for slaughter pigs. Fouling of the pen happens when pigs change their excretory behaviour from occurring in the designated dunging area to the lying area. This can result in a lower hygiene, bad air quality, extra work...... that also fits the weight of the pigs in different stages of the production. All in all, fouling of the pen in conventional slaughter pigs is a multifactorial problem, but it is important to focus on increasing the comfortability, and especially the climate, of the designated lying area....

  9. Filtration Behaviour and Fouling Mechanisms of Polysaccharides

    Directory of Open Access Journals (Sweden)

    Sondus Jamal

    2014-07-01

    Full Text Available This study investigated filtration behaviors of polysaccharides solutions, both alone and in mixture with proteins, in the short-time constant flux filtration with the focus on factors affecting the transmembrane pressure (TMP increase rate, the irreversible filtration resistance, and the membrane rejection behavior. The results showed that the TMP increase rates in the short-time constant flux filtration of alginate solutions were significantly affected by the calcium addition, alginate concentration, and flux. Although the addition of calcium resulted in a decrease in the TMP increase rate, it was found that the irreversible fouling developed during the filtration increased with the calcium addition, implying that the double-sided effect of calcium on membrane filtration and that the TMP increase rate observed in the filtration does not always reflect the irreversible membrane fouling development. It was also found that for the filtration of solutions containing mixed alginate and BSA, alginate exerted a dominant effect on the TMP increase rate and the membrane exhibited a reduced rejection to both alginate and BSA molecules compared to that in the filtration of the pure alginate or BSA.

  10. Developing Boiler Concepts as Integrated Units

    DEFF Research Database (Denmark)

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

    2004-01-01

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

  11. Liquid-infused nitric oxide-releasing (LINORel) silicone for decreased fouling, thrombosis, and infection of medical devices.

    Science.gov (United States)

    Goudie, Marcus J; Pant, Jitendra; Handa, Hitesh

    2017-10-19

    Recent reports on liquid-infused materials have shown promise in creating ultra-low fouling surfaces, but are limited in their ability to prevent bacterial proliferation and prevent platelet activation in blood-contacting applications. In this work, a liquid-infused nitric oxide-releasing (LINORel) material is created by incorporating the nitric oxide (NO) donor S-nitroso-acetylpenicillamine (SNAP) and silicone oil in commercial medical grade silicone rubber tubing through a solvent swelling process. This combination provides several key advantages over previous NO-releasing materials, including decreased leaching of NO donor, controlled release of NO, and maintenance of ultra-low fouling property of liquid-infused materials. The LINORel tubing reduces protein adhesion as observed using fluorescence imaging, and platelet adhesion (81.7 ± 2.5%) in vitro over a 2 h period. The LINORel combination greatly reduces bacterial adhesion and biofilm formation of two most common pathogens responsible for hospital acquired infections: gram-positive Staphylococcus aureus and gram-negative Pseudomonas aeruginosa (99.3 ± 1.9% and 88.5 ± 3.3% respectively) over a 7-day period in a CDC bioreactor environment. Overall, the LINORel approach provides a synergistic combination of active and passive non-fouling approaches to increase biocompatibility and reduce infection associated with medical devices.

  12. 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.

  13. Black liquor combustion validated recovery boiler modeling: Final year report. Volume 1 (Main text and Appendix I, sections 1--4)

    Energy Technology Data Exchange (ETDEWEB)

    Grace, T.M.; Frederick, W.J.; Salcudean, M.; Wessel, R.A.

    1998-08-01

    This project was initiated in October 1990, with the objective of developing and validating a new computer model of a recovery boiler furnace using a computational fluid dynamics (CFD) code specifically tailored to the requirements for solving recovery boiler flows, and using improved submodels for black liquor combustion based on continued laboratory fundamental studies. The key tasks to be accomplished were as follows: (1) Complete the development of enhanced furnace models that have the capability to accurately predict carryover, emissions behavior, dust concentrations, gas temperatures, and wall heat fluxes. (2) Validate the enhanced furnace models, so that users can have confidence in the predicted results. (3) Obtain fundamental information on aerosol formation, deposition, and hardening so as to develop the knowledge base needed to relate furnace model outputs to plugging and fouling in the convective sections of the boiler. (4) Facilitate the transfer of codes, black liquid submodels, and fundamental knowledge to the US kraft pulp industry. Volume 1 contains the main body of the report and the first 4 sections of Appendix 1: Modeling of black liquor recovery boilers -- summary report; Flow and heat transfer modeling in the upper furnace of a kraft recovery boiler; Numerical simulation of black liquor combustion; and Investigation of turbulence models and prediction of swirling flows for kraft recovery furnaces.

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

    International Nuclear Information System (INIS)

    Sedić, Almir; Katulić, Stjepko; Pavković, Danijel

    2014-01-01

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

  15. 40 CFR 65.149 - Boilers and process heaters.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 15 2010-07-01 2010-07-01 false Boilers and process heaters. 65.149... System or a Process § 65.149 Boilers and process heaters. (a) Boiler and process heater equipment and operating requirements. (1) Owners or operators using boilers and process heaters to meet the 98 weight...

  16. 46 CFR 63.25-7 - Exhaust gas boilers.

    Science.gov (United States)

    2010-10-01

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

  17. 49 CFR 230.30 - Lap-joint seam boilers.

    Science.gov (United States)

    2010-10-01

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

  18. 49 CFR 230.36 - Hydrostatic testing of boilers.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Hydrostatic testing of boilers. 230.36 Section 230... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Pressure Testing of Boilers § 230.36 Hydrostatic testing of boilers. (a) Time of test. The...

  19. Seasonal variations in fouling diatom communities on the Yantai coast

    Science.gov (United States)

    Yang, Cuiyun; Wang, Jianhua; Yu, Yang; Liu, Sujing; Xia, Chuanhai

    2015-03-01

    Fouling diatoms are a main component of biofilm, and play an important role in marine biofouling formation. We investigated seasonal variations in fouling diatom communities that developed on glass slides immersed in seawater, on the Yantai coast, northern Yellow Sea, China, using microscopy and molecular techniques. Studies were conducted during 2012 and 2013 over 3, 7, 14, and 21 days in each season. The abundance of attached diatoms and extracellular polymeric substances increased with exposure time of the slides to seawater. The lowest diatom density appeared in winter and the highest species richness and diversity were found in summer and autumn. Seasonal variation was observed in the structure of fouling diatom communities. Pennate diatoms Cylindrotheca, Nitzschia, Navicula, Amphora, Gomphonema, and Licmophora were the main fouling groups. Cylindrotheca sp. dominated in the spring. Under laboratory culture conditions, we found that Cylindrotheca grew very fast, which might account for the highest density of this diatom in spring. The lower densities in summer and autumn might result from the emergence of fouling animals and environmental factors. The Cylindrotheca sp. was identified as Cylindrotheca closterium using18S rDNA sequencing. The colonization process of fouling diatoms and significant seasonal variation in this study depended on environmental and biological factors. Understanding the basis of fouling diatoms is essential and important for developing new antifouling techniques.

  20. Electrical design requirements for electrode boilers for nuclear plants

    International Nuclear Information System (INIS)

    Kempker, M.J.

    1979-01-01

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

  1. Environmental performance assessment of utility boiler energy conversion systems

    International Nuclear Information System (INIS)

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

    2016-01-01

    Highlights: • Sustainability analyses of utility boilers are performed. • Natural gas fired boilers have the least CO 2 emissions in fossil fueled boilers. • Solar boilers rank last with an emergy yield ratio of 1.2. • Biomass boilers have the best emergy sustainability index. - Abstract: A significant amount of global electric power generation is produced from the combustion of fossil fuels. Steam boilers are one of the most important components for steam and electricity production. The objective of this paper is to establish a theoretical framework for the sustainability analysis of a utility boiler. These analyses can be used by decision-makers to diagnose and optimize the sustainability of a utility boiler. Seven utility boiler systems are analyzed using energy and embodied solar energy (emergy) principles in order to evaluate their environmental efficiencies. They include a subcritical coal fired boiler, a supercritical coal fired boiler, an oil fired boiler, a natural gas fired boiler, a concentrating solar power boiler utilizing a tower configuration, a biomass boiler, and a refuse derived fuel boiler. Their relative environmental impacts were compared. The results show that the natural gas boiler has significantly lower CO 2 emission than an equivalent coal or oil fired boiler. The refuse derived fuel boiler has about the same CO 2 emissions as the natural gas boiler. The emergy sustainability index of a utility boiler system is determined as the measure of its sustainability from an environmental perspective. Our analyses results indicate that the natural gas boiler has a relatively high emergy sustainability index compared to other fossil fuel boilers. Converting existing coal boilers to natural gas boilers is a feasible option to achieve better sustainability. The results also show that the biomass boiler has the best emergy sustainability index and it will remain a means to utilize the renewable energy within the Rankine steam cycle. Before

  2. 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.

  3. Fouling-resistant polymer brush coatings

    KAUST Repository

    Thérien-Aubin, Héloïse

    2011-11-01

    A major problem to be addressed with thin composite films used in processes such as coatings or water purification is the biofouling of the surface. To address this problem in a model system, functionalized polyaramide membranes containing an atom transfer radical polymerization (ATRP) initiator were synthesized as a versatile approach to easily modify the surface properties of the polyaramide. Poly(methacrylic acid) brushes were grown using surface initiated ATRP followed by the functionalization of the poly(methacrylic acid) brushes with different side-chains chosen to reduce adhesion between the membrane and foulant. The relation between membrane fouling and the physicochemical properties of the surface was investigated in detail. © 2011 Elsevier Ltd. All rights reserved.

  4. Microbial fouling control in heat exchangers

    International Nuclear Information System (INIS)

    McCoy, W.F.

    1991-01-01

    Biofilm formation in turbulent flow has been studied a great deal during the last 15 years. Such studies have provided the basis for further experiments designed to test the efficacy of industrial antimicrobials against biofilms in laboratory models and in actual real-world industrial water-treatment programs. Biofilm microbiology is relevant from the industrial perspective because adherent populations of microorganisms often cause an economic impact on industrial processes. For example, it is the adherent population of microorganisms in cooling-water systems that can eventually contribute to significant heat transfer and fluid frictional resistances. The microbiology of biofilms in heat exchangers can be related to the performance of industrial antimicrobials. The development of fouling biofilms and methods to quantitatively observe the effect of biofouling control agents are discussed in this paper

  5. Fouling and slagging problems at recovered wood fuel combustion; Orsaker till askrelaterade driftproblem vid eldning av returtraeflis

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Christer; Hoegberg, Jan [Vattenfall Utveckling AB, Stockholm (Sweden)

    2001-03-01

    CHP-plants that use a large portion of sorted wood waste fuel can face ash-related problems. By analysing the circumstances about these problems, the goal is to find causes for the problems and measures that can be taken. This knowledge can then be utilised in plants where it is desired to increase the portion of sorted wood waste fuel. For the measurements, a deposit probe is a good tool to use since the result is independent of many boiler-specific factors. Compared with forest residues, sorted wood waste causes a more problematic ash. The risk of troublesome fouling and corrosion seems to increase with increased admixture of sorted wood waste fuel. Plugging of the grate is associated with melts that are formed from metallic contamination in the fuel. These melts obstruct the air holes. The melts that have been seen during the project have had a content of aluminium, brass and zinc. In order to solve these problems, the construction and cooling of the grate and quality assurance of the fuel are important aspects. One problem that was found in all of the studied boilers (grates as well as fluidized beds) is growth of fouling on surfaces for heat transfer. Measurements with deposit probe show that the initial growth rate on superheaters are approximately 3 - 5 times higher when sorted wood waste is used than if forest residues is used. Even if this growth rate can not be extrapolated to a complete operating season, the relative difference between the fuels remains. The extent of the problem depends on the dimensioning of the boiler. The fouling tends to have a light outer layer that can be disadvantageous for the absorption of heat radiation. Haendeloe P11 needs for example to be stopped for cleaning with an interval of 2 - 3 months because of lost heat absorption in the furnace and the convection path. The most obvious ash related problem that was found in Haendeloe P11 when 100 % sorted wood waste fuel was used was corrosion on the walls of the lower parts of the

  6. Coal-water slurry fuel combustion testing in an oil-fired industrial boiler. Semiannual technical progress report, August 15, 1993--February 15, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Miller, B.G.; Morrison, J.L.; Poe, R.L.; Scaroni, A.W.

    1994-11-30

    The Pennsylvania State University is conducting a coal-water slurry fuel (CWSF) program with the objective of determining the viability of firing CWSF in an industrial boiler designed for heavy fuel oil. The project will also provide information to help in the design of new systems specifically configured to fire these clean coal-based fuels. The project consists of four phases: (1) design, permitting, and test planning, (2) construction and start up, (3) demonstration and evaluation (1,000-hour demonstration), and (4) expanded demonstration and evaluation (installing a CWSF preparation circuit, conducting an additional 1,000 hours of testing, and installing an advanced flue gas treatment system). The boiler testing and evaluation will determine if the CWSF combustion characteristics, heat release rate, fouling and slagging behavior, corrosion and erosion tendencies, and fuel transport, storage, and handling characteristics can be accommodated in a boiler system designed to fire heavy fuel oil. In addition, the proof-of-concept demonstration will generate data to determine how the properties of a CWSF and its parent coal affect boiler performance. The economic factors associated with retrofitting boilers will also be evaluated. The first demonstrations been completed and the combustion performance of the burner that was provided with the boiler has been determined to be unacceptable. Consequently, the first demonstration has been concluded at 500 hours. The second demonstration will be conducted after a proven CWSF-designed burner is installed on the boiler. During this reporting period, the construction of the fuel preparation facility that will contain the CWSF circuit (as well as a dry, micronized coal circuit) was completed. Proposals from potential suppliers of the flue gas treatment systems were reviewed by Penn State and DOE.

  7. Coal-water slurry fuel combustion testing in an oil-fired industrial boiler. Semiannual technical progress report, February 15, 1994--August 15, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Miller, B.G.; Scaroni, A.W.

    1994-11-30

    The Pennsylvania State University is conducting a coal-water slurry fuel (CWSF) program for the United States Department of Energy (DOE) and the Commonwealth of Pennsylvania with the objective of determining the viability of firing CWSF in an industrial boiler designed for heavy fuel oil. The project will also provide information to help in the design of new system specifically configured to fire these clean coal-based fuels. The project consists of four phases: (1) design, permitting, and test planning, (2) construction and start up, (3) demonstration and evaluation (1,000-hour demonstration), and (4) expanded demonstration and evaluation (installing a CWSF preparation circuit, conducting an additional 1,000 hours of testing, and installing an advanced flue gas treatment system). The boiler testing and evaluation will determine if the CWSF combustion characteristics, heat release rate, fouling and slagging behavior, corrosion and erosion tendencies, and fuel transport, storage, and handling characteristics can be accommodated in a boiler system designed to fire heavy fuel oil. In addition, the proof-of-concept demonstration will generate data to determine how the properties of a CWSF and its parent coal affect boiler performance. The economic factors associated with retrofitting boilers will also be evaluated. During this reporting period, the construction of the CWSF preparation circuit (as well as a dry, micronized coal circuit) continued. The CWSF preparation circuit will be completed by November 1,1994. Additional activities included receiving a coal-designed burner and installing it on the demonstration boiler, and working with DOE in selecting pollution control systems to install on the boiler.

  8. Impact of sludge flocs on membrane fouling in membrane bioreactors

    DEFF Research Database (Denmark)

    Christensen, Morten Lykkegaard; Niessen, Wolfgang; Jørgensen, Mads Koustrup

    of divalent ions such as calcium and iron. Furthermore, it was shown that the ratio between cations and EPS was important for the fouling potential of the sludge. A high ratio between divalent ions and EPS reduced membrane fouling as soluble EPS were adsorbed and bound within the sludge flocs. Strong compact...... flocs reduced membrane fouling, and more compact and strong flocs were formed if the concentration of divalent ions were high. Sludge was fractionated by centrifugation providing supernatant with soluble EPS and colloidal particles but without flocs. Filtration test on untreated sludge and supernatant...

  9. Chemical cleaning of UK AGR boilers

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  10. Regression analysis of pulsed eddy current signals for inspection of steam generator tube support structures

    International Nuclear Information System (INIS)

    Buck, J.; Underhill, P.R.; Mokros, S.G.; Morelli, J.; Krause, T.W.; Babbar, V.K.; Lepine, B.

    2015-01-01

    Nuclear steam generator (SG) support structure degradation and fouling can result in damage to SG tubes and loss of SG efficiency. Conventional eddy current technology is extensively used to detect cracks, frets at supports and other flaws, but has limited capabilities in the presence of multiple degradation modes or fouling. Pulsed eddy current (PEC) combined with principal components analysis (PCA) and multiple linear regression models was examined for the inspection of support structure degradation and SG tube off-centering with the goal of extending results to include additional degradation modes. (author)

  11. Experimental study on fouling in the heat exchangers of surface water heat pumps

    International Nuclear Information System (INIS)

    Bai, Xuelian; Luo, Te; Cheng, Kehui; Chai, Feng

    2014-01-01

    Fouling in the heat exchangers plays a key role on the performance of surface water heat pumps. It is also the basement for the system design criteria and operation energy efficiency. In this paper, experimental measurements are performed both in the field and the laboratory with different water qualities, temperatures and velocities. The research will focus on the dynamic growth characteristics of fouling and its main components. By studying the variation rules of fouling resistance, the fouling resistance allowance for certain water condition is recommended. Furthermore, a fouling prediction model in surface water heat pump will be developed and validated based on elaborating with fouling principle under specified water conditions. - Highlights: • Field and laboratory experiments are taken to measure the fouling variation. • Fouling growth process can be divided into four stages. • We recommend fouling resistance allowances for certain conditions. • A fouling prdiction model is developed and validated

  12. Boiler economy. Terms and application

    International Nuclear Information System (INIS)

    Boehm, G.

    1995-01-01

    Economy calculations are nearly exclusively made by computers. Undisputed advantage is apart from the high speed in which even complex calculations are made the 'document character' of the printout. Disadvantageous is that apart from the soft manufacturer almost nobody knows the calculation formulations, basic assumptions and logical connections. One can only accept the result without being able to prove the 'correctness'. There is also hardly the possibility to gain knowledge as the reason for certain results is not explained. Based on known terms of boiler economy many questions arising in practice can be answered with sufficient accuracy. Excessive accuracy is with the many unknown or only estimated operating data anyhow not reasonable. (orig.) [de

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

    Energy Technology Data Exchange (ETDEWEB)

    Mike Bockelie; Kevin Davis; Connie Senior Darren Shino; Dave Swenson; Larry Baxter; Calvin Bartholomew; William Hecker; Stan Harding

    2004-09-30

    This is the seventeenth 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. The SCR slipstream reactor was assembled and installed at Plant Gadsden this quarter. Safety equipment for ammonia had not been installed at the end of the quarter, but will be installed at the beginning of next quarter. The reactor will be started up next quarter. Four ECN corrosion probes were reinstalled at Gavin and collected corrosion data for approximately one month. Two additional probes were installed and removed after about 30 hours for future profilometry analysis. Preliminary analysis of the ECN probes, the KEMA coupons and the CFD modeling results all agree with the ultrasonic tube test measurements gathered by AEP personnel.

  14. Treatment of Berkeley boilers in Studsvik. Project description and experiences - Berkeley Boilers Project

    International Nuclear Information System (INIS)

    Saul, Dave; Davidson, Gavin; Wirendal, Bo

    2014-01-01

    In November 2011 Studsvik was awarded a contract to transport five decommissioned boilers from the Berkeley Nuclear Licensed Site in the UK to the Studsvik Nuclear Site in Sweden for metal treatment and recycling. A key objective of the project was to remove the boilers from the site by 31 March 2012 and this was successfully achieved with all boilers off site by 22 March and delivered to Studsvik on 6 April. In November 2012 Studsvik was awarded a further contract for the remaining ten Berkeley Boilers with the requirement to remove all boilers from the Berkeley site by 31 March 2013. Again this was successfully achieved ahead of programme with all boilers in Sweden by 1 April 2013. A total of nine boilers have now been processed and all remaining boilers will be completed by end of September 2014. The projects have had many challenges including a very tight timescale and both have been successfully delivered to cost and ahead of the baseline programme. This paper describes the project and the experience gained from treatment of the boilers to date. (authors)

  15. Model track studies on fouled ballast using ground penetrating radar and multichannel analysis of surface wave

    Science.gov (United States)

    Anbazhagan, P.; Lijun, Su; Buddhima, Indraratna; Cholachat, Rujikiatkamjorn

    2011-08-01

    Ballast fouling is created by the breakdown of aggregates or outside contamination by coal dust from coal trains, or from soil intrusion beneath rail track. Due to ballast fouling, the conditions of rail track can be deteriorated considerably depending on the type of fouling material and the degree of fouling. So far there is no comprehensive guideline available to identify the critical degree of fouling for different types of fouling materials. This paper presents the identification of degree of fouling and types of fouling using non-destructive testing, namely seismic surface-wave and ground penetrating radar (GPR) survey. To understand this, a model rail track with different degree of fouling has been constructed in Civil engineering laboratory, University of Wollongong, Australia. Shear wave velocity obtained from seismic survey has been employed to identify the degree of fouling and types of fouling material. It is found that shear wave velocity of fouled ballast increases initially, reaches optimum fouling point (OFP), and decreases when the fouling increases. The degree of fouling corresponding after which the shear wave velocity of fouled ballast will be smaller than that of clean ballast is called the critical fouling point (CFP). Ground penetrating radar with four different ground coupled antennas (500 MHz, 800 MHz, 1.6 GHz and 2.3 GHz) was also used to identify the ballast fouling condition. It is found that the 800 MHz ground coupled antenna gives a better signal in assessing the ballast fouling condition. Seismic survey is relatively slow when compared to GPR survey however it gives quantifiable results. In contrast, GPR survey is faster and better in estimating the depth of fouling.

  16. 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.

  17. Scaling and particulate fouling in membrane filtration systems

    NARCIS (Netherlands)

    Boerlage, S.F.E.

    2001-01-01

    Membrane filtration technologies have emerged as cost competitive and viable techniques in drinking and industrial water production. Despite advancements in membrane manufacturing and technology, membrane scaling and fouling remain major problems and may limit future growth in the industry. Scaling

  18. Abundance of bacterial and diatom fouling on various surfaces

    Digital Repository Service at National Institute of Oceanography (India)

    PrabhaDevi

    Abundance of bacterial and diatom fouling on aluminium, fibreglass and stainless steel were studied from Dona Paula waters of the Zuari Estuary. Both these forms were reversibly attached in large numbers to surfaces during the initial 24 hr...

  19. Fouling Kinetics and Associated Dynamics of Structural Modifications

    DEFF Research Database (Denmark)

    Jacob, Jerome; Prádanos, Pedro; Calvo, J. I.

    1998-01-01

    It is shown that the fouling behaviour of microfiltration membranes does not agree within all the time ranges of any of the commonly used membrane blocking models (i.e. complete, standard, intermediate or cake blocking). The resulting experimental kinetics of flux decline do not fit to only one...... of these models, but according to a successive or simultaneous coexistence of two or more of them. This is studied by analysing the structural modifications associated with the fouling kinetics. To achieve this goal, here we analyse the dynamical changes on the structure of four microporous membranes made...... by Sartorius (ST02 and ST045, neutral) and Spectrum (SP02 and SP045, positively charged) when fouled by permeating a protein aqueous solution (bovine serum albumin (BSA) at 1 g l(-1)) under 10 kPa in a dead-end device. The structure after different fouling times is obtained by using an extended bubble point...

  20. Fouling in small hydro projects; Verschmutzung von Kleinwasserkraftwerken - Schlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Abgottspon, A.; Staubli, T.

    2010-03-15

    This comprehensive final report for the Swiss Federal Office of Energy (SFOE) takes a look at fouling problems encountered in small hydro installations. The report is based on ten interviews made with operators of small hydro power stations in Switzerland. A parallel project carried out in Germany is mentioned. A large variation in the degree of fouling in the various hydro power stations is noted. Sources such as leaves in autumn and algae are discussed, as are the various rinsing procedures used to clear the turbines of fouling. Power losses are discussed and measures that can be taken to prevent fouling are described. Measurements made at an installation in Freienstein, Switzerland, are presented and discussed. The report is completed with an appendix containing calculations, details on the Freienstein power plant and the results of interviews made with the ten hydro power installations examined.

  1. Advanced Ultrasupercritical (AUSC) Tube Membrane Panel Development

    Energy Technology Data Exchange (ETDEWEB)

    Pschirer, James [Alstom Power Inc., Windsor, CT (United States); Burgess, Joshua [Alstom Power Inc., Windsor, CT (United States); Schrecengost, Robert [Alstom Power Inc., Windsor, CT (United States)

    2017-08-16

    Alstom Power Inc., a wholly owned subsidiary of the General Electric Company (GE), has completed the project “Advanced Ultrasupercritical (AUSC) Tube Membrane Panel Development” under U.S. Department of Energy (DOE) Award Number DE-FE0024076. This project was part of DOE’s Novel Crosscutting Research and Development to Support Advanced Energy Systems program. AUSC Tube Membrane Panel Development was a two and one half year project to develop and verify the manufacturability and serviceability of welded tube membrane panels made from high performance materials suitable for the AUSC steam cycles, defined as high pressure steam turbine inlet conditions of 700-760°C (1292-1400°F) and 24.5-35MPa (3500-5000psi). The difficulty of this challenge lies in the fact that the membrane-welded construction imposes demands on the materials that are unlike any that exist in other parts of the boiler. Tube membrane panels have been designed, fabricated, and installed in boilers for over 50 years with relatively favorable experience when fabricated from carbon and Cr-Mo low alloy steels. The AUSC steam cycle requires membrane tube panels fabricated from materials that have not been used in a weldment with metal temperatures in the range of 582-610°C (1080-1130°F). Fabrication materials chosen for the tubing were Grade 92 and HR6W. Grade 92 is a creep strength enhanced ferritic Cr-Mo alloy and HR6W is a high nickel alloy. Once the materials were chosen, GE performed the engineering design of the panels, prepared shop manufacturing drawings, and developed manufacturing and inspection plans. After the materials were purchased, GE manufactured and inspected the tube membrane panels, determined if post fabrication heat treatment of the tube membrane panels was needed, performed pre- and post-weld heat treatment on the Grade 92 panels, conducted final nondestructive inspection of any heat treated tube membrane panels, conducted destructive inspection of the completed tube

  2. Ecological boiler modernization, feasible energy solutions

    International Nuclear Information System (INIS)

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

    2005-01-01

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

  3. CONDENSING ECONOMIZERS FOR SMALL COAL-FIRED BOILERS AND FURNACES PROJECT REPORT - JANUARY 1994

    Energy Technology Data Exchange (ETDEWEB)

    BUTCHER,T.A.

    1994-01-04

    Condensing economizers increase the thermal efficiency of boilers by recovering sensible and latent heat from exhaust gas. These economizers are currently being used commercially for this purpose in a wide range of applications. Performance is dependent upon application-specific factors affecting the utility of recovered heat. With the addition of a condensing economizer boiler efficiency improvements up to 10% are possible. Condensing economizers can also capture flue gas particulates. In this work, the potential use of condensing economizers for both efficiency improvement and control of particulate emissions from small, coal water slurry-fired boilers was evaluated. Analysis was done to predict heat transfer and particulate capture by mechanisms including: inertial impaction, interception, diffusion, thermophoretic forces, and condensation growth. Shell-and-tube geometries were considered with flue gas on the outside of Teflon-covered tubes. Experimental studies were done with both air- and water-cooled economizers refit to a small boiler. Two experimental arrangements were used including oil-firing with injection of flyash upstream of the economizer and direct coal water slurry firing. Firing rates ranged from 27 to 82 kW (92,000 to 280,000 Btu/hr). Inertial impaction was found to be the most important particulate capture mechanism and removal efficiencies to 95% were achieved. With the addition of water sprays directly on the first row of tubes, removal efficiencies increased to 98%. Use of these sprays adversely affects heat recovery. Primary benefits of the sprays are seen to be the addition of small impaction sites and future design improvements are suggested in which such small impacts are permanently added to the highest velocity regions of the economizer. Predicted effects of these added impactors on particulate removal and pressure drop are presented.

  4. Ultrafiltration Membrane Fouling and the Effect of Ion Exchange Resins

    KAUST Repository

    Jamaly, Sanaa

    2011-12-01

    Membrane fouling is a challenging process for the ultrafiltration membrane during wastewater treatment. This research paper determines the organic character of foulants of different kinds of wastewater before and after adding some ion exchange resins. Two advanced organic characterization methods are compared in terms of concentration of dissolved organic carbons: The liquid chromatography with organic carbon (LC-OCD) and Shimadzu total organic carbon (TOC). In this study, two secondary wastewater effluents were treated using ultrafiltration membrane. To reduce fouling, pretreatment using some adsorbents were used in the study. Six ion exchange resins out of twenty were chosen to compare the effect of adsorbents on fouling membrane. Based on the percent of dissolved organic carbon’s removal, three adsorbents were determined to be the most efficient (DOWEX Marathon 11 anion exchange resin, DOWEX Optipore SD2 polymeric adsorbent, and DOWEX PSR2 anion exchange), and three other ones were determined to the least efficient (DOWEX Marathon A2 anion exchange resin, DOWEX SAR anion exchange resin, and DOWEX Optipore L493 polymeric adsorbent). Organic characterization for feed, permeate, and backwash samples were tested using LC-OCD and TOC to better understand the characteristics of foulants to prevent ultrafiltration membrane fouling. The results suggested that the polymeric ion exchange resin, DOWEX SD2, reduced fouling potential for both treated wastewaters. All the six ion exchange resins removed more humic fraction than other organic fractions in different percent, so this fraction is not the main for cause for UF membrane fouling. The fouling of colloids was tested before and after adding calcium. There is a severe fouling after adding Ca2+ to effluent colloids.

  5. Development of a test platform for anti-fouling coatings

    OpenAIRE

    Meskens, R.; Willemen, R.; Potters, G.; De Baere, K.; Lenaerts, S.

    2017-01-01

    Marine fouling, or the growth of marine organisms on fully or partly submerged structures, is an unwanted phenomenon in the marine industry. Bio fouling will increase the hydrodynamic drag of ships, causing an increased fuel consumption, promote the corrosion of the metallic structures and trigger undesired transport of invasive species (IMO and the environment 2009, 2009).The impact is economic as well as environmental. More fuel consumption is synonym for more CO2 and other detrimental emis...

  6. Short Review on Predicting Fouling in RO Desalination

    Science.gov (United States)

    Melián-Martel, Noemi

    2017-01-01

    Reverse Osmosis (RO) membrane fouling is one of the main challenges that membrane manufactures, the scientific community and industry professionals have to deal with. The consequences of this inevitable phenomenon have a negative effect on the performance of the desalination system. Predicting fouling in RO systems is key to evaluating the long-term operating conditions and costs. Much research has been done on fouling indices, methods, techniques and prediction models to estimate the influence of fouling on the performance of RO systems. This paper offers a short review evaluating the state of industry knowledge in the development of fouling indices and models in membrane systems for desalination in terms of use and applicability. Despite major efforts in this field, there are gaps in terms of effective methods and models for the estimation of fouling in full-scale RO desalination plants. In existing models applied to full-scale RO desalination plants, neither the spacer geometry of membranes, nor the efficiency and frequency of chemical cleanings are considered. PMID:29064433

  7. Short Review on Predicting Fouling in RO Desalination

    Directory of Open Access Journals (Sweden)

    Alejandro Ruiz-García

    2017-10-01

    Full Text Available Reverse Osmosis (RO membrane fouling is one of the main challenges that membrane manufactures, the scientific community and industry professionals have to deal with. The consequences of this inevitable phenomenon have a negative effect on the performance of the desalination system. Predicting fouling in RO systems is key to evaluating the long-term operating conditions and costs. Much research has been done on fouling indices, methods, techniques and prediction models to estimate the influence of fouling on the performance of RO systems. This paper offers a short review evaluating the state of industry knowledge in the development of fouling indices and models in membrane systems for desalination in terms of use and applicability. Despite major efforts in this field, there are gaps in terms of effective methods and models for the estimation of fouling in full-scale RO desalination plants. In existing models applied to full-scale RO desalination plants, neither the spacer geometry of membranes, nor the efficiency and frequency of chemical cleanings are considered.

  8. Kinetic study of seawater reverse osmosis membrane fouling

    KAUST Repository

    Khan, Muhammad

    2013-10-01

    Reverse osmosis (RO) membrane fouling is not a static state but a dynamic phenomenon. The investigation of fouling kinetics and dynamics of change in the composition of the foulant mass is essential to elucidate the mechanism of fouling and foulant-foulant interactions. The aim of this work was to study at a lab scale the fouling process with an emphasis on the changes in the relative composition of foulant material as a function of operating time. Fouled membrane samples were collected at 8 h, and 1, 2, and 4 weeks on a lab-scale RO unit operated in recirculation mode. Foulant characterization was performed by CLSM, AFM, ATR-FTIR, pyrolysis GC-MS, and ICP-MS techniques. Moreover, measurement of active biomass and analysis of microbial diversity were performed by ATP analysis and DNA extraction, followed by pyro-sequencing, respectively. A progressive increase in the abundance of almost all the foulant species was observed, but their relative proportion changed over the age of the fouling layer. Microbial population in all the membrane samples was dominated by specific groups/species belonging to Proteobacteria and Actinobacteria phyla; however, similar to abiotic foulant, their relative abundance also changed with the biofilm age. © 2013 American Chemical Society.

  9. Short Review on Predicting Fouling in RO Desalination.

    Science.gov (United States)

    Ruiz-García, Alejandro; Melián-Martel, Noemi; Nuez, Ignacio

    2017-10-24

    Reverse Osmosis (RO) membrane fouling is one of the main challenges that membrane manufactures, the scientific community and industry professionals have to deal with. The consequences of this inevitable phenomenon have a negative effect on the performance of the desalination system. Predicting fouling in RO systems is key to evaluating the long-term operating conditions and costs. Much research has been done on fouling indices, methods, techniques and prediction models to estimate the influence of fouling on the performance of RO systems. This paper offers a short review evaluating the state of industry knowledge in the development of fouling indices and models in membrane systems for desalination in terms of use and applicability. Despite major efforts in this field, there are gaps in terms of effective methods and models for the estimation of fouling in full-scale RO desalination plants. In existing models applied to full-scale RO desalination plants, neither the spacer geometry of membranes, nor the efficiency and frequency of chemical cleanings are considered.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-09-01

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

  11. 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

  12. 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.

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

    International Nuclear Information System (INIS)

    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

  14. MSWI Boiler Ashes: Production and Quality Through the Horizontal Section of a Boiler

    DEFF Research Database (Denmark)

    Allegrini, Elisa; Boldrin, Alessio; Astrup, Thomas Fruergaard

    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...

  15. Reduced Bed Temperature in FB-Boilers Burning Waste - part II; Saenkt baeddtemperatur i FB-pannor foer avfallsfoerbraenning - etapp 2

    Energy Technology Data Exchange (ETDEWEB)

    Niklasson, Fredrik; Pettersson, Anita; Claesson, Frida; Johansson, Andreas; Gunnarsson, Anders; Gyllenhammar, Marianne; Victoren, Anders; Gustafsson, Goeran

    2010-07-01

    This project focuses on evaluating whether lowered bed temperature in FB-boilers for waste combustion gives operational benefits, such as reduced fouling in the convection pass. If so, this mode of operation could reduce the number of unplanned boiler outages, reduce the need for soot blowing, and extend the lifetime of the superheaters at unaltered steam temperature. The project is based on full-scale experiments performed at Ryaverket in Boraas. The plant has two waste-fired 20 MW{sub t} FB-boilers. The study is based on a comparison between operational data and measurement results from two different operating conditions of the boilers. In addition to the data that normally are logged by the control system, samples of fuel, ashes, particles, and deposits were taken and subsequently analyzed. The structure of the bed ash was altered by lowering the bed temperature. Under normal boiler operation, the bed ash contains many small agglomerates that disappeared when the bed temperature was lowered. Due to this, the sand consumption of the plant could be reduced by roughly 25 %. At lowered bed temperature, the concentration of chlorine increased in the bed ash and in the recycled sand while it decreased in the ashes from the cyclone and fabric filter. The concentration of HCl in the flue gas increased as the bed temperature was lowered. This is considered a consequence of less chlorine forming alkali chlorides. Moreover, the particle measurements showed that the amount of submicron particles decreased during lowered bed temperature, which also is an indication of less alkali chlorides in the flue gas. The deposit probes showed an approximate 20 % reduction of the fouling rate when the bed temperature was lowered from 876 to 714 deg C. The chlorine content also decreased in the deposits. For the deposit probes at 500 deg C, (corresponds to a steam temperature of 465 deg C) significant amounts of KCl were found in the deposits, even when the bed temperature was lowered

  16. Superhydrophilic Thin-Film Composite Forward Osmosis Membranes for Organic Fouling Control: Fouling Behavior and Antifouling Mechanisms

    KAUST Repository

    Tiraferri, Alberto

    2012-10-16

    This study investigates the fouling behavior and fouling resistance of superhydrophilic thin-film composite forward osmosis membranes functionalized with surface-tailored nanoparticles. Fouling experiments in both forward osmosis and reverse osmosis modes are performed with three model organic foulants: alginate, bovine serum albumin, and Suwannee river natural organic matter. A solution comprising monovalent and divalent salts is employed to simulate the solution chemistry of typical wastewater effluents. Reduced fouling is consistently observed for the superhydrophilic membranes compared to control thin-film composite polyamide membranes, in both reverse and forward osmosis modes. The fouling resistance and cleaning efficiency of the functionalized membranes is particularly outstanding in forward osmosis mode where the driving force for water flux is an osmotic pressure difference. To understand the mechanism of fouling, the intermolecular interactions between the foulants and the membrane surface are analyzed by direct force measurement using atomic force microscopy. Lower adhesion forces are observed for the superhydrophilic membranes compared to the control thin-film composite polyamide membranes. The magnitude and distribution of adhesion forces for the different membrane surfaces suggest that the antifouling properties of the superhydrophilic membranes originate from the barrier provided by the tightly bound hydration layer at their surface, as well as from the neutralization of the native carboxyl groups of thin-film composite polyamide membranes. © 2012 American Chemical Society.

  17. Superhydrophilic thin-film composite forward osmosis membranes for organic fouling control: fouling behavior and antifouling mechanisms.

    Science.gov (United States)

    Tiraferri, Alberto; Kang, Yan; Giannelis, Emmanuel P; Elimelech, Menachem

    2012-10-16

    This study investigates the fouling behavior and fouling resistance of superhydrophilic thin-film composite forward osmosis membranes functionalized with surface-tailored nanoparticles. Fouling experiments in both forward osmosis and reverse osmosis modes are performed with three model organic foulants: alginate, bovine serum albumin, and Suwannee river natural organic matter. A solution comprising monovalent and divalent salts is employed to simulate the solution chemistry of typical wastewater effluents. Reduced fouling is consistently observed for the superhydrophilic membranes compared to control thin-film composite polyamide membranes, in both reverse and forward osmosis modes. The fouling resistance and cleaning efficiency of the functionalized membranes is particularly outstanding in forward osmosis mode where the driving force for water flux is an osmotic pressure difference. To understand the mechanism of fouling, the intermolecular interactions between the foulants and the membrane surface are analyzed by direct force measurement using atomic force microscopy. Lower adhesion forces are observed for the superhydrophilic membranes compared to the control thin-film composite polyamide membranes. The magnitude and distribution of adhesion forces for the different membrane surfaces suggest that the antifouling properties of the superhydrophilic membranes originate from the barrier provided by the tightly bound hydration layer at their surface, as well as from the neutralization of the native carboxyl groups of thin-film composite polyamide membranes.

  18. Evaluation of the behavior of shrouded plasma spray coatings in the platen superheater of coal-fired boilers

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-06-15

    Nickel- and cobalt-based coatings were formulated by a shrouded plasma spray process on boiler tube steels, namely, ASTM-SA210-grade A1 (GrA1), ASTM-SA213-T-11 (T11), and ASTM-SA213-T-22 (T22). The Ni-22Cr-10A1-1Y alloy powder was sprayed as a bond in each case before the final coating. The degradation behavior of the bared and coated steels was studied in the platen superheater of the coal-fired boiler. The samples were inserted through the soot blower dummy points with the help of stainless steel wires. The coatings were found to be effective in increasing resistance to degradation in the given boiler environment. The maximum protection was observed in the case of Stellite-6 (St-6) coating.

  19. Experimental study of composition and influence factors on fouling of stainless steel and copper in seawater

    International Nuclear Information System (INIS)

    Yang, Dazhang; Liu, Jianhua; E, Xiaoxue; Jiang, Linlin

    2016-01-01

    Highlights: • An increase of seawater temperature deteriorates the fouling and corrosion. • The main compositions of crystals are Mg(OH) 2 , Al(OH) 3 and their complex compounds. • The images of the seawater fouling on stainless steel and copper were shown in the paper. • A higher heat flux and A higher Reynolds number are prone to crystallization fouling accumulation in seawater. - Abstract: Metals and alloys are easily fouled in marine environment. It is a big problem for heat exchangers using cooling seawater in power plants or ships. In the paper, a seawater-fouling dynamic test device was built to investigate the composition and influence factors on fouling of stainless steel and copper in the cooling seawater system. Moreover, the static trials were performed to study the fouling and corrosion of stainless steel and copper in marine environment. The experimental results show that the seawater fouling of stainless steel is crystallization fouling, and the main elements of fouling are magnesium and aluminum. In addition, the results show that the seawater fouling of copper is corrosion fouling. In the dynamic experiments, the effects of heat flux and Reynolds number on stainless steel fouling were studied. The results show that higher heat flux and higher Reynolds number of seawater lead to the accumulation of seawater fouling.

  20. Safety issues arising from the corrosion-fatigue of waterwall tubes

    Energy Technology Data Exchange (ETDEWEB)

    Brear, J. M.; Jarvis, P. (Stress Engineering Services (Europe) Limited, Chichester (United Kingdom)); Scully, S. (Electricity Supply Board, Dublin (Ireland))

    2010-05-15

    An incidence of waterwall tube failures, one leading to a significant steam release external to the boiler, has highlighted the need for rigorous risk assessment of such events. Initial review of the utility's experience revealed one of their boiler designs as having had a greater incidence of corrosion-fatigue issues in waterwall tubing than the others. These units were treated as a priority. To address failure likelihood, fracture mechanics calculations were performed. These studies defined the necessary inspection coverage and sensitivity required to underwrite safe operation at various potential loads. Personnel safety was considered the most important consequence of failure. Accordingly, potential steam releases were modelled to define safe exclusion zones within the boiler house. Standard calculations were found to be nonconservative; more exact formulae were needed to give realistic results. Using the results of these studies, the utility was able to draw up a realistic inspection plan. Safe operating pressures and appropriate exclusion zones were defined for each boiler, and for a range of operational scenarios. These tactics have allowed the utility to inspect the boilers in turn and to repair all significant defects in the waterwall tubes, whilst maintaining a good overall power output. In parallel, a root-cause investigation was performed to identify the factors contributing to the failures. Where possible, causative influences were reduced or mitigated so as to reduce the likelihood of failure whilst allowing increased flexibility of boiler operation. (orig.)

  1. 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.

  2. 46 CFR 52.25-5 - Miniature boilers (modifies PMB-1 through PMB-21).

    Science.gov (United States)

    2010-10-01

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

  3. 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

  4. 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.

  5. Increasing the efficiency of the condensing boiler

    Science.gov (United States)

    Zaytsev, ON; Lapina, EA

    2017-11-01

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

  6. The load structure of electro boilers

    International Nuclear Information System (INIS)

    Feilberg, N.; Livik, K.

    1995-01-01

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

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

    International Nuclear Information System (INIS)

    Munir, A.; Alvi, J.Z.; Ashfaq, S.; Ghafoor, A.

    2014-01-01

    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)

  8. 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.

  9. Improvement of efficiency by proportional and integral control for compact boiler; Shoyoryo boiler no renzoku seigyo (P.I seigyo) ni yoru seino kaizen

    Energy Technology Data Exchange (ETDEWEB)

    Yanagida, T. [Kawasaki Thermal Engineering Co. Ltd., Shiga (Japan)

    1998-10-01

    Efficiency of a compact boiler is improved by the introduction of a continuous P.I. control. It is controlled by the following procedure. The proportional control, which controls magnitude of combustion in proportion to a load requirement, is combined with an integral control function which keeps steam pressure at a given level, in order to stabilize steam pressure at a level comparable to that of a large, water-tube type boiler. A stable steam pressure is realized by including control of make-up water supply, to minimize the effects of water supply on steam pressure. The effects of characteristics of the combustion valve on control are relaxed by programming. In addition to the above, rotational speed of the motor for the forced draft fan is controlled for each load level, to reduce power consumption. These bring improved quality of steam, i.e., stabilized steam pressure, improved follow-up characteristics of the steam and secured dryness of the steam. Energy-saving is also achieved, i.e., reduction of noise and power consumption at a low combustion load are achieved by improved real boiler efficiency and inverter-aided control of the forced draft fan. Low-NOx burners are adopted, to abate NOx content to 60ppm or less at any load. 16 figs.

  10. Regeneration of sulfur-fouled bimetallic Pd-based catalysts.

    Science.gov (United States)

    Chaplin, Brian P; Shapley, John R; Werth, Charles J

    2007-08-01

    Pd-based catalysts provide efficient and selective reduction of several drinking water contaminants, but their long-term application requires effective treatments for catalyst regeneration following fouling by constituents in natural waters. This studytested alumina-supported Pd-Cu and Pd-In bimetallic catalysts for nitrate reduction with H2 after sulfide fouling and oxidative regeneration procedures. Both catalysts were severely deactivated after treatment with microM levels of sulfide. Regeneration was attempted with dissolved oxygen, hydrogen peroxide, sodium hypochlorite, and heated air. Only sodium hypochlorite and heated air were effective regenerants, specifically restoring nitrate reduction rates for a Pd-In/gamma-Al2O3 catalyst from 20% to between 39 and 60% of original levels. Results from ICP-MS revealed that sodium hypochlorite caused dissolution of Cu from the Pd-Cu catalyst but that the Pd-In catalyst was chemically stable over a range of sulfide fouling and oxidative regenerative conditions. Analysis byXPS indicated that PdS and In2S3 complexes form during sulfide fouling, where sulfur is present as S2-, and that regeneration with sodium hypochlorite converts a portion of the S2- to S6+, with a corresponding increase in reduction rates. These results indicate that Pd-In catalysts show exceptional promise for being robust under fouling and regeneration conditions that may occur when treating natural waters.

  11. Factors controlling marine fouling in some Alexandria Harbours, Egypt

    Directory of Open Access Journals (Sweden)

    SH.E. RAMADAN

    2006-12-01

    Full Text Available The present work aims to relate the settlement of marine fouling organisms in three different harbours in Alexandria city which present a wide range of ecological/environmental variations. Theses are the Abu Qir, Eastern and El-Dekheila harbours. Monthly samples of marine fouling were collected from the three harbours by using white roughened polystyrene test panels (12.5x12.5 cm, as well as physicochemical, chemical and other biological data. Results were treated with multivariate statistical analysis (PCA. At the Abu Qir harbour, it was found that water temperature and salinity are the most important environmental factors controlling the temporal distribution of total fouling density, whereas water temperature and chlorophyll a are the most significant environmental factors controlling the total biomass. At the Eastern harbour it was demonstrated that ammonia and phosphate are the most significant environmental factors controlling the temporal distribution and total biomass of fouling organisms. Concerning El-Dekheila harbour, the total density and total biomass of fouling organisms were inversely correlated with the total zooplankton.

  12. The New Performance Calculation Method of Fouled Axial Flow Compressor

    Directory of Open Access Journals (Sweden)

    Huadong Yang

    2014-01-01

    Full Text Available Fouling is the most important performance degradation factor, so it is necessary to accurately predict the effect of fouling on engine performance. In the previous research, it is very difficult to accurately model the fouled axial flow compressor. This paper develops a new performance calculation method of fouled multistage axial flow compressor based on experiment result and operating data. For multistage compressor, the whole compressor is decomposed into two sections. The first section includes the first 50% stages which reflect the fouling level, and the second section includes the last 50% stages which are viewed as the clean stage because of less deposits. In this model, the performance of the first section is obtained by combining scaling law method and linear progression model with traditional stage stacking method; simultaneously ambient conditions and engine configurations are considered. On the other hand, the performance of the second section is calculated by averaged infinitesimal stage method which is based on Reynolds’ law of similarity. Finally, the model is successfully applied to predict the 8-stage axial flow compressor and 16-stage LM2500-30 compressor. The change of thermodynamic parameters such as pressure ratio, efficiency with the operating time, and stage number is analyzed in detail.

  13. Zeta-potential of fouled thin film composite membrane

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, K.; Hachisuka, H.; Nakamura, T. [Nitto denko Corp., Ibaraki, (Japan); Kimura, S. [Kogakuin University, Tokyo (Japan). Dept. of Environ. Chemical Engineering; Ueyama, K. [Osaka University, Osaka (Japan). Dept. of Chemical Engineering

    1999-10-01

    The surface zeta-potential of a cross-linked polyamide thin film composite reverse osmosis membrane was measured using an electrophoresis method. It was confirmed that this method could be effectively applied to analyze the fouling of such membranes. It is known that the water flux of membranes drastically decreases as a result of fouling by surfactants. Although the surfactants adsorbed on reverse osmosis membranes could not be detected by conventional methods such as SEM, EDX and FT-IR, their presence could be clarified by the profile measurements of the surface zeta-potential. The profiles of the membrane surface zeta-potentials changed to more positive values in the measured pH range as a result of fouling by cationic or amphoteric surfactants. This measuring method of surface zeta-potentials allowed us to analyze a very small amount of fouling of a thin film composite reverse osmosis membrane. This method could be used to analyze the fouled surface of the thin film composite reverse osmosis membrane which is used for production of ultrapure water and shows a remarkable decrease in flux. It also became clear that this method is easy and effective for the reverse osmosis membrane surface analysis of adsorbed materials such as surfactants. (author)

  14. In-line quantification and characterization of membrane fouling

    KAUST Repository

    Bucs, Szilard

    2016-06-16

    Methods of detecting, quantifying and/or characterizing the fouling of a device from a combination of pressure and spectroscopic data are provided. The device can be any device containing components susceptible to fouling. Components can include membranes, pipes, or reactors. Suitable devices include membrane devices, heat exchangers, and chemical or bio-reactors. Membrane devices can include, for example, microfiltration devices, ultrafiltration devices, nanofiltration devices, reverse osmosis, forward osmosis, osmosis, reverse electrodialysis, electro- deionisation or membrane distillation devices. The methods can be applied to any type of membrane, including tubular, spiral, hollow fiber, flat sheet, and capillary membranes. The spectroscopic characterization can include measuring one or more of the absorption, fluorescence, or raman spectroscopic data of one or more foulants. The methods can allow for the early detection and/or characterization of fouling. The characterization can include determining the specific foulant(s) or type of foulant(s) present. The characterization of fouling can allow for the selection of an appropriate de-fouling method and timing.

  15. CFD modeling of fouling in crude oil pre-heaters

    International Nuclear Information System (INIS)

    Bayat, Mahmoud; Aminian, Javad; Bazmi, Mansour; Shahhosseini, Shahrokh; Sharifi, Khashayar

    2012-01-01

    Highlights: ► A conceptual CFD-based model to predict fouling in industrial crude oil pre-heaters. ► Tracing fouling formation in the induction and developing continuation periods. ► Effect of chemical components, shell-side HTC and turbulent flow on the fouling rate. - Abstract: In this study, a conceptual procedure based on the computational fluid dynamic (CFD) technique has been developed to predict fouling rate in an industrial crude oil pre-heater. According to the developed CFD concept crude oil was assumed to be composed of three pseudo-components comprising of petroleum, asphaltene and salt. The binary diffusion coefficients were appropriately categorized into five different groups. The species transport model was applied to simulate the mixing and transport of chemical species. The possibility of adherence of reaction products to the wall was taken into account by applying a high viscosity for the products in competition with the shear stress on the wall. Results showed a reasonable agreement between the model predictions and the plant data. The CFD model could be applied to new operating conditions to investigate the details of the crude oil fouling in the industrial pre-heaters.

  16. NOx Control for Utility Boiler OTR Compliance

    Energy Technology Data Exchange (ETDEWEB)

    Hamid Farzan; Jennifer L. Sivy

    2005-07-30

    Babcock & Wilcox Power Generation Group (B&W) and Fuel Tech, Inc. (Fuel Tech) teamed to evaluate an integrated solution for NO{sub x} control comprised of B&W's DRB-4Z{reg_sign} low-NO{sub x} pulverized coal (PC) burner technology and Fuel Tech's NO{sub x}OUT{reg_sign}, a selective non-catalytic reduction (SNCR) technology, capable of meeting a target emission limit of 0.15 lb NO{sub x}/10{sup 6} Btu. In a previous project sponsored by the U.S. Department of Energy (DOE), promising results were obtained with this technology from large-scale testing in B&W's 100-million Btu/hr Clean Environment Development Facility (CEDF) which simulates the conditions of large coal-fired utility boilers. Under the most challenging boiler temperatures at full load conditions, NO{sub x} emissions of 0.19 lb/10{sup 6} Btu were achieved firing Powder River Basin coal while controlling ammonia slip to less than 5 ppm. At a 40 million Btu/hr firing rate, NO{sub x} emissions were as low as 0.09 lb/10{sup 6} Btu. Improved performance with this system was proposed for this new program with injection at full load via a convective pass multiple nozzle lance (MNL) in front of the superheater tubes or in the convective tube bank. Convective pass lances represent the current state-of-the-art in SNCR and needed to be evaluated in order to assess the full potential of the combined technologies. The objective of the program was to achieve a NO{sub x} level below 0.15 lb/10{sup 6} Btu (with ammonia slip of less than 5 ppm) in the CEDF using PRB coal and B&W's DRB-4Z{reg_sign} low-NO{sub x} pulverized coal (PC) burner in combination with dual zone overfire air ports and Fuel Tech's NO{sub x}OUT{reg_sign} System. Commercial installations of B&W's low-NO{sub x} burner, in combination with overfire air ports using PRB coal, have demonstrated a NO{sub x} level of 0.15 to 0.2 lb/10{sup 6} Btu under staged combustion conditions. The proposed goal of the combustion system (no

  17. Aspects of new material application for boilers construction

    International Nuclear Information System (INIS)

    Czerniawski, R.

    1996-01-01

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

  18. 21 CFR 173.310 - Boiler water additives.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Boiler water additives. 173.310 Section 173.310... FOR HUMAN CONSUMPTION (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Specific Usage Additives § 173.310 Boiler water additives. Boiler water additives may be safely...

  19. 46 CFR 176.812 - Pressure vessels and boilers.

    Science.gov (United States)

    2010-10-01

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

  20. 10 CFR 431.82 - Definitions concerning commercial packaged boilers.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Definitions concerning commercial packaged boilers. 431.82... COMMERCIAL AND INDUSTRIAL EQUIPMENT Commercial Packaged Boilers § 431.82 Definitions concerning commercial packaged boilers. The following definitions apply for purposes of this subpart E, and of subparts A and J...

  1. 46 CFR 115.812 - Pressure vessels and boilers.

    Science.gov (United States)

    2010-10-01

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

  2. 40 CFR 761.71 - High efficiency boilers.

    Science.gov (United States)

    2010-07-01

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

  3. 46 CFR 109.205 - Inspection of boilers and machinery.

    Science.gov (United States)

    2010-10-01

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

  4. 40 CFR 63.988 - Incinerators, boilers, and process heaters.

    Science.gov (United States)

    2010-07-01

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

  5. Optimal load allocation of multiple fuel boilers.

    Science.gov (United States)

    Dunn, Alex C; Du, Yan Yi

    2009-04-01

    This paper presents a new methodology for optimally allocating a set of multiple industrial boilers that each simultaneously consumes multiple fuel types. Unlike recent similar approaches in the utility industry that use soft computing techniques, this approach is based on a second-order gradient search method that is easy to implement without any specialized optimization software. The algorithm converges rapidly and the application yields significant savings benefits, up to 3% of the overall operating cost of industrial boiler systems in the examples given and potentially higher in other cases, depending on the plant circumstances. Given today's energy prices, this can yield significant savings benefits to manufacturers that raise steam for plant operations.

  6. Boiler inspection manipulator for Torness Power Station

    International Nuclear Information System (INIS)

    Carrey, R.T.A.; Yule, I.Y.; Sibson, S.; Playle, M.J.

    1996-01-01

    The Advanced Gas-cooled Reactors at Torness and Heysham 2 are provided with dedicated access for remote inspection equipment. These in-service inspection (ISI) accesses comprise 12 penetrations above the core for inspection of the above core area and boilers, 12 below core penetrations for inspection of the lower boiler area and access through any of the 8 gas circulator penetrations for inspection of the sub-diagrid area. This paper describes a manipulator which will access the reactor from above the core via any of the 8 peripheral penetrations. (UK)

  7. 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.

  8. Dynamic coating of mf/uf membranes for fouling mitigation

    KAUST Repository

    Tabatabai, S. Assiyeh Alizadeh

    2017-01-19

    A membrane system including an anti-fouling layer and a method of applying an anti-fouling layer to a membrane surface are provided. In an embodiment, the surface is a microfiltration (MF) or an ultrafiltration (UF) membrane surface. The anti-fouling layer can include a stimuli responsive layer and a dynamic protective layer applied over the stimuli responsive layer that can be a coating on a surface of the membrane. The stimuli responsive polymer layer can act as an adhesive prior to coating with the dynamic protective layer to aid in adhering the dynamic protective layer to the membrane surface. The dynamic protective layer can be formed by suitable nanoparticles that can prevent adhesion of foulants directly to the membrane surface. The stimuli responsive layer can be responsive to physio- chemical stimuli to cause a release of the stimuli responsive layer and the dynamic protective layer including foulants from the membrane.

  9. A Short Review of Membrane Fouling in Forward Osmosis Processes

    Science.gov (United States)

    Chun, Youngpil; Mulcahy, Dennis; Zou, Linda; Kim, In S.

    2017-01-01

    Interest in forward osmosis (FO) research has rapidly increased in the last decade due to problems of water and energy scarcity. FO processes have been used in many applications, including wastewater reclamation, desalination, energy production, fertigation, and food and pharmaceutical processing. However, the inherent disadvantages of FO, such as lower permeate water flux compared to pressure driven membrane processes, concentration polarisation (CP), reverse salt diffusion, the energy consumption of draw solution recovery and issues of membrane fouling have restricted its industrial applications. This paper focuses on the fouling phenomena of FO processes in different areas, including organic, inorganic and biological categories, for better understanding of this long-standing issue in membrane processes. Furthermore, membrane fouling monitoring and mitigation strategies are reviewed. PMID:28604649

  10. A Short Review of Membrane Fouling in Forward Osmosis Processes.

    Science.gov (United States)

    Chun, Youngpil; Mulcahy, Dennis; Zou, Linda; Kim, In S

    2017-06-12

    Interest in forward osmosis (FO) research has rapidly increased in the last decade due to problems of water and energy scarcity. FO processes have been used in many applications, including wastewater reclamation, desalination, energy production, fertigation, and food and pharmaceutical processing. However, the inherent disadvantages of FO, such as lower permeate water flux compared to pressure driven membrane processes, concentration polarisation (CP), reverse salt diffusion, the energy consumption of draw solution recovery and issues of membrane fouling have restricted its industrial applications. This paper focuses on the fouling phenomena of FO processes in different areas, including organic, inorganic and biological categories, for better understanding of this long-standing issue in membrane processes. Furthermore, membrane fouling monitoring and mitigation strategies are reviewed.

  11. Mechanistic understanding of fouling of protein A chromatography resin.

    Science.gov (United States)

    Pathak, Mili; Rathore, Anurag S

    2016-08-12

    This paper aims to provide a thorough understanding of how fouling of Protein A resin takes place. Binding and mass transport properties of widely used agarose-based Protein A resin, MabSelect SuRe™, have been examined to understand the mechanism of resin fouling. There could be various factors that impact resin fouling. These include product/impurity build-up due to components in the feed material and ligand degradation due to the use of harsh buffers. To unravel their contributions, cycling studies were performed with and without product loading. The results presented in this paper provide a lucid understanding of the causative factors that limit Protein A chromatographic resin lifetime. The capacity fall for protein A resin at the end of 100th cycle due to use of feed material was found to be five times greater than that without using feed material. Compared to the fresh resin, the cycled resin samples shows 24% reduction in particle porosity and 51% reduction in pore mass transfer coefficient. Transmission electron microscopy (TEM) was used to qualitatively monitor accumulation of foulants on the cycled resin. Fouled resin sample contained a dense residue in the interior and exterior of resin particle both as a film at the bead surface and as granules. The surface activation energy increased five times in the case of fouled resin sample. The major event in fouling was identified as the non-specific adsorption of the feed material components on resin, signaling that pore diffusion is the rate limiting step. It is anticipated that these findings will assist in development of a more robust and economical downstream manufacturing process for monoclonal antibody purification. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Industrial fouling: problem characterization, economic assessment, and review of prevention, mitigation, and accommodation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Garrett-Price, B.A.; Smith, S.A.; Watts, R.L.

    1984-02-01

    A comprehensive overview of heat exchanger fouling in the manufacturing industries is provided. Specifically, this overview addresses: the characteristics of industrial fouling problems; the mitigation and accommodation techniques currently used by industry; and the types and magnitude of costs associated with industrial fouling. A detailed review of the fouling problems, costs and mitigation techniques is provided for the food, textile, pulp and paper, chemical, petroleum, cement, glass and primary metals industries.

  13. Online fouling detection in electrical circulation heaters using neural networks

    Energy Technology Data Exchange (ETDEWEB)

    Lalot, S. [M.E.T.I.E.R., Longuenesse Cedex (France); Universite de Valenciennes (France). LME; Lecoeuche, S. [M.E.T.I.E.R., Longuenesse Cedex (France); Universite de Lille (France). Laboratoire 13D

    2003-06-01

    Here is presented a method that is able to detect fouling during the service of a circulation electrical heater. The neural based technique is divided in two major steps: identification and classification. Each step uses a neural network, the connection weights of the first one being the inputs of the second network. Each step is detailed and the main characteristics and abilities of the two neural networks are given. It is shown that the method is able to discriminate fouling from viscosity modification that would lead to the same type of effect on the total heat transfer coefficient. (author)

  14. Fouling-induced enzyme immobilization for membrane reactors

    DEFF Research Database (Denmark)

    Luo, Jianquan; Meyer, Anne S.; Jonsson, Gunnar Eigil

    2013-01-01

    A simple enzyme immobilization method accomplished by promoting membrane fouling formation is proposed. The immobilization method is based on adsorption and entrapment of the enzymes in/on the membrane. To evaluate the concept, two membrane orientations, skin layer facing feed (normal mode......, but the reverse mode allowed for higher enzyme loading and stability, and irreversible fouling (i.e. pore blocking) developed more readily in the support structure than in the skin layer. Compared with an enzymatic membrane reactor (EMR) with free enzymes, the novel EMR with enzymes immobilized in membrane...... support improved the enzyme reusability (especially for ADH), and reduced the product inhibition (especially for GDH). © 2013 Elsevier Ltd....

  15. Cleaning protocol for a FO membrane fouled in wastewater reuse

    KAUST Repository

    Valladares Linares, Rodrigo

    2013-05-30

    Forward osmosis (FO) is an emerging technology which can be applied in water reuse applications. Osmosis is a natural process that involves less energy consumption than reverse osmosis (RO), and therefore can be applied as a dilution process before low-pressure RO; it is expected to compete favourably against current advanced water reuse technologies that use microfiltration/ultrafiltration and RO. The focus of this research was to assess the efficiency of different cleaning procedures to remove fouling from the surface of a FO membrane during the operation of a submerged system working in FO-mode (active layer (AL) facing feed solution) intended for secondary wastewater effluent (SWWE) recovery, using seawater as draw solution (DS), which will be diluted and can further be fed to a low-pressure RO unit to produce fresh water. Natural organic matter (NOM) fouling was expected to affect the AL, while for the support layer (SL), transparent exopolymer particles (TEP) were used as indicators of fouling due to their stickiness and propensity to enhance the attachment of other foulants in seawater on the membrane surface. The composition of the NOM fouling layer was determined after proper characterisation with a liquid chromatograph coupled with organic carbon detection (LC-OCD), showing biopolymers and protein-like substances as the main constituents. NOM fouling showed high hydraulic reversibility after a 25% flux decline was observed, up to 89.5% when in situ air scouring for 15 min was used as a cleaning technique. Chemical cleaning with a mixture of Alconox, an industrial detergent containing phosphates, and sodium EDTA showed to increase the reversibility (93.6%). Osmotic backwash using a 4% NaCl solution and DI water proved to be ineffective to recover flux due to the salt diffusion phenomena occurring at the AL. Part of the flux that could not be recovered is attributable to TEP fouling on the SL, which forms clusters clearly identifiable with an optical

  16. Membrane Fouling and Chemical Cleaning in Three Full-Scale Reverse Osmosis Plants Producing Demineralized Water

    NARCIS (Netherlands)

    Beyer, Florian; Laurinonyte, Judita; Zwijnenburg, Arie; Stams, Alfons J.M.; Plugge, Caroline M.

    2017-01-01

    Membrane fouling and cleaning were studied in three reverse osmosis (RO) plants. Feed water was secondary wastewater effluent, river water, and surface water. Membrane autopsies were used for fouling characterization. Fouling layer measurements included total organic carbon (TOC), adenosine

  17. A New Concept of Ultrafiltration Fouling Control : Backwashing with Low Ionic Strength Water

    NARCIS (Netherlands)

    Li, S.

    2011-01-01

    Ultrafiltration (UF) is a proven technology in water treatment nowadays. However, fouling remains a major challenge in the operation of UF, especially in regard to colloidal NOM fouling. In general, a number of colloidal NOM fouling mechanisms may occur, such as adsorption, gel formation. Colloidal

  18. Evaluation of laboratory crude oil threshold fouling data for application to refinery pre-heat trains

    Energy Technology Data Exchange (ETDEWEB)

    Polley, G.T. [Ulverston, Cumbria (United Kingdom); Wilson, D.I.; Yeap, B.L. [University of Cambridge, (United Kingdom). Department of Chemical Engineering; Pugh, S.J. [ESDU International plc, London (United Kingdom)

    2002-07-01

    'Threshold' models for crude oil fouling present a logical framework for analysing chronic fouling problems in refinery pre-heat trains. Few complete data sets of fouling thresholds in crude oil exist: this paper presents a modelling (correlation) study of the data set obtained by Knudsen et al. [Understanding Heat Exchanger Fouling and its Mitigation, Begell House, New York, 1999, p. 265] for threshold fouling experiments performed in a pilot plant. The threshold fouling equation proposed previously by Ebert and Panchal, and extended by Panchal et al. [Understanding Heat Exchanger Fouling and its Mitigation, Begell House, New York, 1999, p. 273] has been modified following a critique of some of its underlying assumptions. These previous efforts in developing threshold fouling equations were based on observed fouling rates, extrapolated to yield operating conditions that presumably exhibit zero fouling. This study represents an attempt to model measured physical parameters that actually resulted in no observable fouling. The validity of such a model to describe threshold fouling conditions in refinery pre-heat exchangers is discussed. (author)

  19. Protein fouling in carbon nanotubes enhanced ultrafiltration membrane: Fouling mechanism as a function of pH and ionic strength

    KAUST Repository

    Lee, Jieun

    2016-11-04

    The protein fouling behavior was investigated in the filtration of the multiwall carbon nanotube (MWCNT) composite membrane and commercial polyethersulfone ultrafiltration (PES-UF) membrane. The effect of solution chemistry such as pH and ionic strength on the protein fouling mechanism was systematically examined using filtration model such as complete pore blocking, intermediate pore blocking and cake layer formation. The results showed that the initial permeate flux pattern and fouling behavior of the MWCNT composite membrane were significantly influenced by pH and ionic strength while the effect of PES-UF membrane on flux was minimal. In a lysozyme (Lys) filtration, the severe pore blocking in the MWCNT membrane was made by the combined effect of intra-foulant interaction (Lys-Lys) and electrostatic repulsion between the membrane surface and the foulant at pH 4.7 and 10.4, and increasing ionic strength where the foulant-foulant interaction and membrane-fouling interaction were weak. In a bovine serum albumin (BSA) filtration, severe pore blocking was reduced by less deposition via the electrostatic interaction between the membrane and foulant at pH 4.7 and 10.4 and increasing ionic strength, at which the interaction between the membrane and BSA became weak. For binary mixture filtration, the protein fouling mechanism was more dominantly affected by foulant-foulant interaction (Lys-BSA, Lys-Lys, and BSA-BSA) at pH 7.0 and increase in ionic strength. This research demonstrates that MWCNT membrane fouling can be alleviated by changing pH condition and ionic strength based on the foulant-foulant interaction and the electrostatic interaction between the membrane and foulant.

  20. The investigation of the locomotive boiler material

    International Nuclear Information System (INIS)

    Tucholski, Z.; Wasiak, J.; Bilous, W.; Hajewska, E.

    2006-01-01

    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)

  1. 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.

  2. 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 ...

  3. Ion exchange resin fouling of molybdenum in recovery uranium processess

    International Nuclear Information System (INIS)

    Zhang Guowei; Zhao Guirong

    1990-09-01

    The relationship between anion exchange resin fouling and molybdic acid polymerization was studied. By using potentiometer titration and laser-Raman spectroscopy the relationship of molybdic acid polymerization and the pH value of solution or the molybdenum concentration was determined. It was shown that as the concentration of initial molybdenum in solution decreases from 0.2 mol/L to 0.5 mmol/L, the pH value of starting polymerization decreased from 6.5 to 4.5. The experimental results show that the fouling of 201 x 7 resin in the acidic solution is mainly caused by the adsorbing of Mo 3 O 26 4- ion and occupying the exchange radical site of the resin. Under the leaching conditions the molybdenum and phosphate existing in the leaching liquor can form 12-molybdo-phosphate ion. It also leads to resin fouling. The molybdenum on the fouled resin can synergically be desorbed by mixed desorbents containing ammonium hydroxide and ammonium sulfate. The desorbed resin can be used for uranium adsorption and the desorbed molybdenum can be recovered by ion exchange method

  4. Experimental investigation of fouling characteristics of diesel oil ...

    African Journals Online (AJOL)

    This study investigated the fouling characteristics of diesel oil using hot-wire test equipment. The diesel oil was electrically preheated to a desired fluid temperature using a heating coil. The fluid entered the test section and swept through a nichrome wire which was supplied with the electrical current corresponding to the ...

  5. 49 CFR 236.724 - Circuit, shunt fouling.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, shunt fouling. 236.724 Section 236.724 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RULES, STANDARDS, AND INSTRUCTIONS GOVERNING THE INSTALLATION, INSPECTION...

  6. Factors Influencing Membrane fouling in the MBR Process

    Directory of Open Access Journals (Sweden)

    Parvin Nahid

    2018-01-01

    Full Text Available Biological processes of wastewater treatmnent have found wide applications due to their lower costs and higher efficiency. Membrane bioreactors (MBR’s form one group of such processes in which membrane fouling is of great importance. Efficiency of critical flux (CF has been proved to be a parameter effective in fouling control (CF. CF is itself influenced by three main groups of variables that include sludge parameters, operating conditions, and membrane types. In this stidy, the effects of such factors as trans-membrane pressure, protein and carbohydrate concentrations in extracellular polymeric substances (EPS, and soluble microbial products (SMP on CF were investigated in a submerged MBR.  Moreover, the effects of such operating conditions as periodic and continuous suctions at two sludge concentrations were studied. It was found that increasing flux led to enhanced membrane fouling rates. Extracellular polymeric substances (EPS were found to have no relations with critical flux (CF, probably because EPS are mostly found as bigger flocks. Finally, a reverse relationship was established between CF and carbohydrate concentration of the SMP. Membrane fouling control was observed to be positively affected by the rest modes during periodic suctions.

  7. Fouling and boring organisms that deteriorate various European ...

    African Journals Online (AJOL)

    This study aims to investigate the diversity of fouling and boring organisms damaging wood material at Turkish coasts. Trials were carried out at six harbour sites throughout the seas surrounding Turkey. Various Euopean and tropical wood samples were hanged down at a depth of six meters in the sea for a period of one ...

  8. Reduced fouling of ultrafiltration membranes via surface fluorination

    Energy Technology Data Exchange (ETDEWEB)

    Sedath, R.H.; Yates, S.F.; Li, N.N.

    1993-03-01

    Surface fluorination can affect significantly the performance of an ultrafiltration membrane used to concentrate a food-related stream. Membranes fluorinated and tested as flat sheets exhibit higher initial fluxes, and do not foul as rapidly as untreated membranes. This improvement is linked to increased surface hydrophilicity, as shown in decreased contact angle with water. This increased hydrophilicity, in turn, is linked to the addition of fluorine and oxygen to the surface. The pilot plant study did-not show the difference in membrane flux and fouling observed in the flat sheet study. Instead, fluorinated and unfluorinated modules behaved similarly. Fouling by potato waste feed was severe and resulted in formation of an extensive gel layer within the module on the membrane surface. XPS, SEM and FTIR indicate that buildup of organic material occurred on both fluorinated and unfluorinated membranes, but SEM indicates that a fibrous mat of material was observed only on the nonfluorinated membrane. We conclude that in the pilot study, membrane fouling and gel formation were so extensive that the surface interaction effect was overwhelmed.

  9. Biomimetic non-fouling surfaces: extending the concepts

    Czech Academy of Sciences Publication Activity Database

    Pop-Georgievski, Ognen; Rodriguez-Emmenegger, Cesar; de los Santos Pereira, Andres; Proks, Vladimír; Brynda, Eduard; Rypáček, František

    2013-01-01

    Roč. 1, č. 22 (2013), s. 2859-2867 ISSN 2050-750X R&D Projects: GA ČR GAP205/12/1702; GA MŠk(CZ) LH13178; GA ČR GAP108/11/1857 Institutional support: RVO:61389013 Keywords : non-fouling * polymer brushes * polydopamine Subject RIV: CD - Macromolecular Chemistry

  10. Characterization of a non-fouling ultrafiltration membrane

    DEFF Research Database (Denmark)

    Wei, J.; Helm, G.S.; Corner-Walker, N.

    2006-01-01

    This report describes the properties of surface-modified poly(vinylidene fluoride) (PVDF) membranes. These membranes were created by coating hydrophilic polymers on the support PVDF membrane to reduce the tendency to protein fouling. The modified membranes with different molecular weight cut-off ...

  11. Structure-performance-fouling studies of polysulfone microfiltration ...

    Indian Academy of Sciences (India)

    of the pore diameter due to swelling of PVP (Wienk et al. 1995; Qin et al 2003). Removal of PVP from such membrane using hypochlorite treatment may enhance the water flux as hypochlorite leached the PVP by chain scission. Fouling is a matter of great concern for all pressure-driven membrane processes. Systematic ...

  12. Experimental study of micro-particle fouling under forced convective heat transfer

    Directory of Open Access Journals (Sweden)

    S. M. Peyghambarzadeh

    2012-12-01

    Full Text Available Particulate fouling studies of a hydrocarbon based suspension containing 2 µm alumina particles were performed in an annular heat exchanger having a hydraulic diameter of 14.7 mm. During fouling experiments, the classical asymptotical behavior was observed. It is shown that particle concentration, fluid velocity, and wall temperature have strong influences on the fouling curve and the asymptotic fouling resistance. Furthermore, a mathematical model is developed to formulate the asymptotic fouling resistance in terms of the mass transfer coefficient, thermophoresis velocity, and fluid shear rate. The results demonstrate that the prediction of the new model is in good agreement with the experimental observations.

  13. Membrane fouling mechanism transition in relation to feed water composition

    KAUST Repository

    Myat, Darli Theint

    2014-12-01

    The impact of secondary effluent wastewater from the Eastern Treatment Plant (ETP), Melbourne, Australia, before and after ion exchange (IX) treatment and polyaluminium chlorohydrate (PACl) coagulation, on hydrophobic polypropylene (PP) and hydrophilic polyvinylidene fluoride (PVDF) membrane fouling was studied. Laboratory fouling tests were operated over 3-5 days with regular, intermittent backwash. During the filtration with PP membranes, organic rejection data indicated that humic adsorption on hydrophobic PP membrane occurred during the first 24h of filtration and contributed to fouling for both raw wastewater and pre-treated wastewaters. However, after the first 24h of filtration the contribution of humic substances to fouling diminished and biopolymers that contribute to cake layer development became more prominent in their contribution to the fouling rate. For PVDF membranes, the per cent removal of humic substances from both raw wastewater and pre-treated wastewaters was very small as indicated by no change in UV254 from the feed to the permeate over the filtration period, even during the early stages of filtration. This suggested that the hydrophobic PP membrane adsorbed humic substances while the hydrophilic PVDF membrane did not. The highest mass of biopolymer removal by each PVDF membrane was from ETP water followed by PACl and IX treated water respectively. This was possibly due to differences in the backwashing efficiency linked to the filter cake contributed by biopolymers. Hydraulic backwashing was more effective during the later stages of filtration for the ETP water compared to IX and PACl treated waters, indicating that the filter cake contributed by ETP biopolymers was more extensively removed by hydraulic backwashing. It was proposed that humic substances may act to stabilise biopolymers in solution and that removing humics substances by coagulation or IX results in greater adhesive forces between the biopolymers and membrane/filter cake

  14. Coal-water slurry fuel combustion testing in an oil-fired industrial boiler. Semiannual technical progress report, February 15--August 15, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Miller, B.G.; Scaroni, A.W.

    1997-06-03

    The project consists of four phases: (1) design, permitting, and test planning, (2) construction and start up, (3) demonstration and evaluation (1,000-hour demonstration), and (4) expanded demonstration and evaluation (installing a CWSF preparation circuit, performing baseline tests firing No. 6 fuel oil, and conducting additional CWSF testing). The boiler testing and evaluation will determine if the CWSF combustion characteristics, heat release rate, fouling and slagging behavior, corrosion and erosion tendencies, and fuel transport, storage, and handling characteristics can be accommodated in a boiler system designed to fire heavy fuel oil. In addition, the proof-of-concept demonstration will generate data to determine how the properties of a CWSF and its parent coal affect boiler performance. The economic factors associated with retrofitting boilers is also evaluated. The first three phases have been completed and the combustion performance of the burner that was provided with the boiler did not meet performance goals. A maximum coal combustion efficiency of 95% (compared to a target of 98%) was achieved and natural gas cofiring (15% of the total thermal input) was necessary to maintain a stable flame. Consequently, the first demonstration was terminated after 500 hours. The second CWSF demonstration (Phase 4) was conducted with a proven coal-designed burner. Prior to starting the second demonstration, a CWSF preparation circuit was constructed to provide flexibility in CWSF production. The circuit initially installed involved single-stage grinding. A regrind circuit was recently installed and was evaluated. A burner was installed from ABB Combustion Engineering (ABB/CE) and was used to generate baseline data firing No. 6 fuel oil and fire CWSF. A temporary storage system for No. 6 fuel oil was installed and modifications to the existing CWSF handling and preheating system were made to accommodate No. 6 oil.

  15. Rejection of micropollutants by clean and fouled forward osmosis membrane

    KAUST Repository

    Valladares Linares, Rodrigo

    2011-12-01

    As forward osmosis (FO) gains attention as an efficient technology to improve wastewater reclamation processes, it is fundamental to determine the influence of fouling in the rejection of emerging contaminants (micropollutants). This study focuses on the rejection of 13 selected micropollutants, spiked in a secondary wastewater effluent, by a FO membrane, using Red Sea water as draw solution (DS), differentiating the effects on the rejection caused by a clean and fouled membrane. The resulting effluent was then desalinated at low pressure with a reverse osmosis (RO) membrane, to produce a high quality permeate and determine the rejection with a coupled forward osmosis - low pressure reverse osmosis (FO-LPRO) system. When considering only FO with a clean membrane, the rejection of the hydrophilic neutral compounds was between 48.6% and 84.7%, for the hydrophobic neutrals the rejection ranged from 40.0% to 87.5%, and for the ionic compounds the rejections were between 92.9% and 96.5%. With a fouled membrane, the rejections were between 44.6% and 95.2%, 48.7%-91.5% and 96.9%-98.6%, respectively. These results suggest that, except for the hydrophilic neutral compounds, the rejection of the micropollutants is increased by the presence of a fouling layer, possibly due to the higher hydrophilicity of the FO fouled membrane compared to the clean one, the increased adsorption capacity of hydrophilic compounds and reduced mass transport capacity, membrane swelling, and the higher negative charge of the membrane surface, related to the foulants composition, mainly NOM acids (carboxylic radicals) and polysaccharides or polysaccharide-like substances. However, when coupled with RO, the rejections in both cases increased above 96%. The coupled FO-LPRO system was an effective double barrier against the selected micropollutants. © 2011 Elsevier Ltd.

  16. The use of titanium for condenser tube bundles

    International Nuclear Information System (INIS)

    Dobrovitch, N.

    2002-01-01

    In a power plant, the condenser is a strategic heat exchanger with regards to the efficiency of the steam turbine and its reliability guarantees the performance and continuous operation of the plant. Until the early 1980's, copper alloys were routinely used in condenser tubes, thanks to their high heat transfer rates. Yet numerous problems arose from the use of this material, such as stress cracking corrosion, ammoniacal corrosion, fouling, erosion, dezincification, abrasion, erosion-corrosion,... and lately the problem of inadequateness of copper with nuclear steam generators (in nuclear power plant the abrasion problem of the copper alloy tubes created a deposit problem in the steam generator conducting to the replacement of all the condensers). The trend was then to consider new tube materials, such stainless steel and titanium, firstly for particular operating conditions and now for most of the projects, with several objectives, such as: 1) improve the reliability (titanium in particular can bring major improvements such as higher water velocities promoting better heat coefficients, excellent resistance to abrasion, erosion and corrosion thereby improving resistance to fouling; 2) find more cost-effective solutions. The first investment is higher but money is saved on maintenance costs and on time reliability of the material. Titanium tube manufacturing has greatly evolved for the last 20 years. Tubes are mostly welded tubes from ASTM SB 338 grade 1 made on a continuous manufacturing line. All manufacturing operations (welding, annealing, non-destructive testing) are fully automated to produce high quality tubes in large quantities. The most common way to attach tubes to a tubesheet is to roller expand them. (A.C.)

  17. Medium pressure boiler water chemistry optimization using neutralizing amines mixture reagent AMINAT™ PK-2 at CEPP “Borovichi Refractories Plant” of JSC “BKO”

    Science.gov (United States)

    Guseva, O. V.; Butakova, M. V.; Orlov, K. A.; Vinogradov, S. V.; Pavlenko, L. S.

    2017-11-01

    An overview of the neutralizing amine based reagent AMINAT PK-2 usage for water chemistry of steam boilers for medium pressure boiler was given. Long term experiment showed that new reagent allows to decrease corrosion rate comparing with old water chemistry based on ammonia only. Two dosage schemes in different cycle places discussed. Scheme with two points on injection showed better results. Results of corrosion rates experiments and photos of tubes inner surfaces are presented. Based on fuel savings due to reducing scale formation the total annual economy for last year was 5.1 million Russian roubles.

  18. Intelligent Image Recognition System for Marine Fouling Using Softmax Transfer Learning and Deep Convolutional Neural Networks

    Directory of Open Access Journals (Sweden)

    C. S. Chin

    2017-01-01

    Full Text Available The control of biofouling on marine vessels is challenging and costly. Early detection before hull performance is significantly affected is desirable, especially if “grooming” is an option. Here, a system is described to detect marine fouling at an early stage of development. In this study, an image of fouling can be transferred wirelessly via a mobile network for analysis. The proposed system utilizes transfer learning and deep convolutional neural network (CNN to perform image recognition on the fouling image by classifying the detected fouling species and the density of fouling on the surface. Transfer learning using Google’s Inception V3 model with Softmax at last layer was carried out on a fouling database of 10 categories and 1825 images. Experimental results gave acceptable accuracies for fouling detection and recognition.

  19. 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

  20. 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.

  1. Neutron tubes

    Science.gov (United States)

    Leung, Ka-Ngo [Hercules, CA; Lou, Tak Pui [Berkeley, CA; Reijonen, Jani [Oakland, CA

    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.

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

    Science.gov (United States)

    Lane Community Coll., Eugene, OR.

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

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

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Electric hot water supply boilers. 63.25-3 Section 63.25... AUXILIARY BOILERS Requirements for Specific Types of Automatic Auxiliary Boilers § 63.25-3 Electric hot water supply boilers. (a) Electric hot water supply boilers that have a capacity not greater than 454...

  4. 46 CFR 52.25-7 - Electric boilers (modifies PEB-1 through PEB-19).

    Science.gov (United States)

    2010-10-01

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

  5. 40 CFR 76.6 - NOX emission limitations for Group 2 boilers.

    Science.gov (United States)

    2010-07-01

    ... boilers. 76.6 Section 76.6 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... for Group 2 boilers. (a) Beginning January 1, 2000 or, for a unit subject to section 409(b) of the Act... owner or operator of a Group 2, coal-fired boiler with a cell burner boiler, cyclone boiler, a wet...

  6. 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.

  7. Foul Play in Sport as a Phenomenon Inconsistent with the Rules, yet Acceptable and Desirable: Ethical Conditions

    Directory of Open Access Journals (Sweden)

    Kosiewicz Jerzy

    2014-06-01

    Full Text Available The article has strictly a theoretical and non-empirical character. The author presents examples resulting from various observations. The aim of the paper is to present the causes, functions, and results of fouls, fouling, and foul play. Although fouls do not comply with the rules of games, the paper demonstrates that fouls are often used; they enjoy a quiet acceptance of the sporting world; they are tolerated and accepted; even more, they are often - more or less explicitly - desirable.

  8. 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.)

  9. Chemical cleaning of boilers and corrosion protection

    International Nuclear Information System (INIS)

    Elhosary, A.A.

    1993-01-01

    While being assembled and installed, thermal-power equipment accumulates a large amount of corrosion products, scale (as much as 350 g/m 2 ), welding residue, and other contaminants that must be removed before the equipment is started up. This is generally done with various acids and inhibitors. For boilers this chemical cleaning process is termed pre start cleaning. In contrast, an operational cleaning of boilers is also carried out, in order to remove carbonate deposits, that interfere with heat transfer, as well as the corrosion products that accumulate with use. The techniques include rinsing with water to remove contaminants not firmly adhering to the metal surfaces, decreasing in alkali reagents to remove grease and to loosen scale, pickling in mineral and organic acids for scale removal, and passivation of the metal surface. decreasing is usually carried out in alkali reagents used are caustic soda, soda ash, tri sodium phosphate ammonia, and surface-active agents

  10. Circulating fluidized bed boiler numerical modeling

    Energy Technology Data Exchange (ETDEWEB)

    Di Maggio, T. [Electricite de France, 75 - Paris (France). Direction des Etudes et Recherches; Bursi, J.M.; Lafanechere, L.; Jestin, L. [Electricite de France (EDF), 69 - Villeurbanne (France); Roulet, V. [E.D.F./DE/CNET, 92 - La Defense (France)

    1996-12-31

    Electricite de France (EdF) is actively involved in the development of CFB power plants. Thanks to a wide Research and Development program around the 125 MWe Emile Huchet and the 250 MWe Provence units (two boilers designed by Stein-Lurgi), EdF has been able to get a good knowledge of hydrodynamics and heat transfer in the circulating loop as well as the back pass. One of the main objectives of the R and D program was to gather this information and results in a steady state operating model of a CFB boiler and to simulate the operation of the 250 MWe Provence power plant. This model has been developed before the first ignition of the Provence power plant in order to check the design and to help on-field engineers during the start-up phase. Furthermore, this model allows R and D engineers to make parametric studies and to evaluate new designs. (authors) 5 refs.

  11. 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

  12. Understanding ozone mechanisms to alleviate ceramic membrane fouling

    Science.gov (United States)

    Chu, Irma Giovanna Llamosas

    Ceramic membranes are a strong prospect as an advanced treatment in the drinking water domain. But their high capital cost and the lack of specific research on their performance still discourage their application in this field. Thus, knowing that fouling is the main drawback experienced in filtration processes, this bench-scale study was aimed to assess the impact of an ozonation pre-treatment on the alleviation of the fouling of UF ceramic membranes. Preozonation and filtration steps were performed under two different pH and ozone doses. Chosen pH values were at the limits of natural surface waters range (6.5 and 8.5) to keep practicability. Raw water from the Thousand Isle's river at Quebec-Canada was used for the tests. The filtration setup involved an unstirred dead-end filtration cell operated at constant flux. Results showed that pre-oxidation by ozone indeed reduced the fouling degree of the membranes according to the dose applied (up to 60 and 85% for membranes 8 and 50 kDa, respectively). Direct NOM oxidation was found responsible for this effect as the presence of molecular ozone was not essential to achieve these results. In the context of this experiment, however, pH showed to be more effective than the ozonation pre-treatment to keep fouling at low levels: 70% lower at pH 6.5 than at pH 8.5 for un-ozonated waters, which was contrary to most of the literature found on the topic (Changwon, 2013; De Angelis & Fidalgo, 2013; Karnik et al., 2005; S. Lee & Kim, 2014). This behaviour results mainly from the operation mode used in the experiment, the electrical repulsions between MON molecules at basic pH that led to the accumulation of material on the feed side of the membranes (concentration polarisation) and ulterior cake formation. In addition, solution pH showed an influence in the definition of fouling mechanisms. At solution pH 6.5, which was precisely the isoelectric point of the membranes (+/-6.5), the blocking fouling mode was frequently detected

  13. High temperature oxidation in boiler environment of chromized steel

    Science.gov (United States)

    Alia, F. F.; Kurniawan, T.; Asmara, Y. P.; Ani, M. H. B.; Nandiyanto, A. B. D.

    2017-10-01

    The demand for increasing efficiency has led to the development and construction of higher operating temperature power plant. This condition may lead to more severe thickness losses in boiler tubes due to excessive corrosion process. Hence, the research to improve the corrosion resistance of the current operated material is needed so that it can be applied for higher temperature application. In this research, the effect of chromizing process on the oxidation behaviour of T91 steel was investigated under steam condition. In order to deposit chromium, mixture of chromium (Cr) powder as master alloy, halide salt (NH4Cl) powder as activator and alumina (Al2O3) powder as inert filler were inserted into alumina retort together with the steel sample and heated inside furnace at 1050°C for ten hours under argon gas environment. Furthermore, for the oxidation process, steels were exposed at 700°C at different oxidation time (6h-24h) under steam condition. From FESEM/EDX analysis, it was found that oxidation rate of pack cemented steel was lower than the un-packed steel. These results show that Cr from chromizing process was able to become reservoir for the formation of Cr2O3 in high temperature steam oxidation, and its existence can be used for a longer oxidation time.

  14. 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.

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

    DEFF Research Database (Denmark)

    Jensen, Peter Arendt

    technology a long range of research studies have been conducted, to improve our understanding of the influence and behavior of biomass ash species in suspension fired boilers. The fuel ash plays a key role with respect tooptimal boiler operation and influences phenomena’s as boiler chamber deposit formation...... formation in suspension fired boilers. The presentation provides an overview of the knowledge obtained with respect to ash species behavior insuspension fired biomass boilers. A mechanistic understanding of the fly ash formation process in biomass fired PF boilers isobtained today. A high fraction of alkali...... salt species are released to the gas phase during the initial fuel combustion process. The salt species are present in gas phase in the boil chamberand upon cooling in the convective pass aerosols are formed. Recent studies indicates that a large fraction of the residual condensed phase ash fragments...

  16. 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.

  17. 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.

  18. Boiler systems for nuclear powered reactors

    International Nuclear Information System (INIS)

    Cook, R.K.; George, B.V.

    1979-01-01

    A power generating plant which comprises a heat source, at least one main steam turbine and at least one main boiler heated by heat from the heat source and providing the steam to drive the turbine, comprises additionally at least one further steam turbine, smaller than the main turbine, and at least one further boiler, of lower capacity than the main boiler, and heated from the same heat source and providing steam for the further turbine. Particularly advantageous in nuclear power stations, where the heat source is a nuclear reactor, the invention enables peak loads, above the normal continuous rating of the main generators driven by the main turbines, to be met by the further turbine(s) and one or more further generators driven thereby. This enables the main turbines to be freed from the thermal stresses of rapid load changes, which stresses are more easily accommodated by the smaller and thus more tolerant further turbine(s). Thus auxiliary diesel-driven or other independent power plant may be made partly or wholly unnecessary. Further, low-load running which would be inefficient if achieved by means of the main turbine(s), can be more efficiently effected by shutting them down and using the smaller further turbine(s) instead. These latter may also be used to provide independent power for servicing the generating plant during normal operation or during emergency or other shutdown, and in this latter case may also serve as a heat sink for the shutdown reactor

  19. 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.

  20. Experimental study of flow patterns near tube support structures

    International Nuclear Information System (INIS)

    Rummens, H.E.C.; Turner, C.W.

    1994-07-01

    Extensive blockage of broached support plates in steam generators has occurred at the Bruce A Nuclear Generating Station (NGS), forcing unit derating in 1988 March. Blockage has also been found on the lower broached plates of the Pickering B and Point Lepreau NGSs. Water chemistry and operating conditions are known to influence fouling directly. We suspect that flow patterns also play a role, that these patterns are influenced by the geometry of steam generator (SG) components, and that particularly the broached plate design actively creates an environment favorable to deposition. Experiments are in progress to examine the flow patterns near various tube supports: the broached plate, two types of lattice bars, and the formed bars. Preliminary tests in an air/water loop with 1/2- and 7-tube SG mockups containing the tube supports have been completed. Flow patterns were visualized using injected air bubbles. Local velocities and turbulence levels were measured using a laser technique, which confirmed observations of flow recirculation and stagnation. Axial pressure profiles were measured to determine overall resistance coefficients, and to identify local pressure extremes. Some visualization tests were also carried out on an artificially fouled broached plate. Based on results to date, several deposition mechanisms are proposed: deposition of particles in stagnant regions, deposition of solubles due to flashing in low-pressure regions, and deposition in smaller channels due to steam migration toward larger channels. A qualitative assessment of the tube support designs based on these mechanisms implies that the relative resistances to fouling are: (WORST) broach plate << lattice bars << formed bars (BEST). As the air/water simulation shows only hydraulic flow patterns, further tests will be done in a simple liquid/vapor Freon loop to examine thermal effects. (author). 3 refs., 10 figs

  1. Performance evaluation of a once-through multi-stage flash distillation system: Impact of brine heater fouling

    International Nuclear Information System (INIS)

    Baig, Hasan; Antar, Mohamed A.; Zubair, Syed M.

    2011-01-01

    Multi-stage flash distillation (MSF) system modeling involves a number of process variables. An estimation of all these process variables requires both analytical solutions and experimental/field analysis. However, the accurate estimate of variables related to the brine heater operation in a MSF system is very important for a reliable operation of the system. For example, steam operating conditions as well as the brine properties including fouling of the brine heater tubes have a significant effect on the heat transfer characteristics of the brine heater, which in turn influence the distillate output from the system. In this study, the effect of various design as well as operating conditions on the performance ratio (PR), brine temperature and salinity as it leaves the last flash stage are investigated in a once-through system. Increasing the number of stages from 24 to 32 has a significant effect on the PR, it ranges between 79% (for ΔT = 1.5) and 327% (for ΔT = 2.3) for a top-brine temperature of 106 o C. This value increase as the top-brine temperature increases. Increasing the stage-to-stage temperature difference increases the water salinity as it leaves the final stage and reduces its temperature that would imply better energy utilization within the plant. Results show that brine side heat exchanger fouling has a significant effect in decreasing the overall heat transfer coefficient, which reduces the production rate as the fouling increases with time. A sensitivity analysis to identify the key parameters, which can have a significant influence on the desalination plant performance, is carried out in an attempt to contribute a better understanding and operation of MSF desalination processes.

  2. ASME Based Quality Documentation Guidelines for Power- and Recovery Boilers

    OpenAIRE

    Lappalainen, Tuomas

    2015-01-01

    The goal of this thesis was to create ASME-based quality documentation guidelines for power- and recovery boilers. The client was a large international power- and recovery boiler manufacturer. The content of this thesis is mainly a report of ASME code and its effects on quality documentation. In thesis are widely compared ASME based quality documention differences between PED/EN projects quality documentation. Also ASMEs most important elements for power- and recovery boiler projects needs fo...

  3. Optimisation of Marine Boilers using Model-based Multivariable Control

    OpenAIRE

    Solberg, Brian

    2008-01-01

    Traditionally, marine boilers have been controlled using classical single loop controllers. To optimise marine boiler performance, reduce new installation time and minimise the physical dimensions of these large steel constructions, a more comprehensive and coherent control strategy is needed. This research deals with the application of advanced control to a specific class of marine boilers combining well-known design methods for multivariable systems.This thesis presents contributions for mo...

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

    International Nuclear Information System (INIS)

    Razzell, R.N.

    1988-01-01

    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)

  5. Radiological investigation in the boiler's maintenance operations in a Coal-Fired power plant

    International Nuclear Information System (INIS)

    Robles, Beatriz; Mora, Juan C.; Cancio, David; Baeza, Antonio; Corbacho, Jose A.

    2008-01-01

    As part of a study being performed in the four biggest coal-fired power plants in Spain, the formation of scales of radioisotopes in parts of the heat recovery system was investigated. This effect should be more important in the case of 210 Po and 210 Pb. Thereby, it is likely in given specific chemical conditions that scales could be formed with a high concentration of 210 Pb, probably in secular equilibrium with 210 Po and 210 Bi. Those scales could reach activity concentrations of some hundreds of Bq g -1 . In order to study within the boiler this scale formation, an investigation during the maintenance operations programmed in the 'Compostilla' coal-fired power plant (Ponferrada-Spain) was carried out. Those operations are performed each 2-3 years and last for around 30 or 40 days. Measurements of ambient dose equivalent (H * (10)) in the boiler before and after the entrance of the operators, together with beta surface contamination on the bottom ashes attached in the walls and on the tubes, were performed. The last measurements were carried out for screening purposes in order to select those areas on the tubes which could present Po scales. Even if chemical conditions are in general oxidising within the boiler, since conditions are not homogeneous, some zones were localized in which surface contamination was measured. In these spots, samples were collected and then measured in the laboratory. Moreover, an analysis of maintenance tasks, used personal protection equipment, working times and other important parameters was also carried out. This analysis is important in order to perform radiological evaluations, as realistic as possible, of the effective doses that could be received by maintenance operators. In the present study, the values of the measurements performed and the results of the assessment of the effective doses for the workers are presented. (author)

  6. Robust design optimization method for centrifugal impellers under surface roughness uncertainties due to blade fouling

    Science.gov (United States)

    Ju, Yaping; Zhang, Chuhua

    2016-03-01

    Blade fouling has been proved to be a great threat to compressor performance in operating stage. The current researches on fouling-induced performance degradations of centrifugal compressors are based mainly on simplified roughness models without taking into account the realistic factors such as spatial non-uniformity and randomness of the fouling-induced surface roughness. Moreover, little attention has been paid to the robust design optimization of centrifugal compressor impellers with considerations of blade fouling. In this paper, a multi-objective robust design optimization method is developed for centrifugal impellers under surface roughness uncertainties due to blade fouling. A three-dimensional surface roughness map is proposed to describe the nonuniformity and randomness of realistic fouling accumulations on blades. To lower computational cost in robust design optimization, the support vector regression (SVR) metamodel is combined with the Monte Carlo simulation (MCS) method to conduct the uncertainty analysis of fouled impeller performance. The analyzed results show that the critical fouled region associated with impeller performance degradations lies at the leading edge of blade tip. The SVR metamodel has been proved to be an efficient and accurate means in the detection of impeller performance variations caused by roughness uncertainties. After design optimization, the robust optimal design is found to be more efficient and less sensitive to fouling uncertainties while maintaining good impeller performance in the clean condition. This research proposes a systematic design optimization method for centrifugal compressors with considerations of blade fouling, providing a practical guidance to the design of advanced centrifugal compressors.

  7. Impact of effluent organic matter on low-pressure membrane fouling in tertiary treatment

    KAUST Repository

    Ayache, C.

    2013-05-01

    This study aims at comparing low-pressure membrane fouling obtained with two different secondary effluents at bench and pilot-scale based on the determination of two fouling indices: the total fouling index (TFI) and the hydraulically irreversible fouling index (HIFI). The main objective was to investigate if simpler and less costly bench-scale experimentation can substitute for pilot-scale trials when assessing the fouling potential of secondary effluent in large scale membrane filtration plants producing recycled water. Absolute values for specific flux and total fouling index for the bench-scale system were higher than those determined from pilot-scale, nevertheless a statistically significant correlation (r2 = 0.63, α = 0.1) was obtained for the total fouling index at both scales. On the contrary no such correlation was found for the hydraulically irreversible fouling index. Advanced water characterization tools such as excitation-emission matrix fluorescence spectroscopy (EEM) and liquid chromatography with organic carbon detection (LC-OCD) were used for the characterization of foulants. On the basis of statistical analysis, biopolymers and humic substances were found to be the major contribution to total fouling (r2 = 0.95 and r2 = 0.88, respectively). Adsorption of the low molecular weight neutral compounds to the membrane was attributed to hydraulically irreversible fouling (r2 = 0.67). © 2013 Elsevier Ltd.

  8. Fouling on ion-exchange membranes: Classification, characterization and strategies of prevention and control.

    Science.gov (United States)

    Mikhaylin, Sergey; Bazinet, Laurent

    2016-03-01

    The environmentally friendly ion-exchange membrane (IEM) processes find more and more applications in the modern industries in order to demineralize, concentrate and modify products. Moreover, these processes may be applied for the energy conversion and storage. However, the main drawback of the IEM processes is a formation of fouling, which significantly decreases the process efficiency and increases the process cost. The present review is dedicated to the problematic of IEM fouling phenomena. Firstly, the major types of IEM fouling such as colloidal fouling, organic fouling, scaling and biofouling are discussed along with consideration of the main factors affecting fouling formation and development. Secondly, the review of the possible methods of IEM fouling characterization is provided. This section includes the methods of fouling visualization and characterization as well as methods allowing investigations of characteristics of the fouled IEMs. Eventually, the reader will find the conventional and modern strategies of prevention and control of different fouling types. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Contribution of effluent organic matter (EfOM) to ultrafiltration (UF) membrane fouling: Isolation, characterization, and fouling effect of EfOM fractions

    KAUST Repository

    Zheng, Xing

    2014-11-01

    EfOM has been regarded as a major organic foulant resulting in UF membrane fouling in wastewater reclamation. To investigate fouling potential of different EfOM fractions, the present study isolated EfOM into hydrophobic neutrals (HPO-N), colloids, hydrophobic acids (HPO-A), transphilic neutrals and acids (TPI), and hydrophilics (HPI), and tested their fouling effect in both salt solution and pure water during ultrafiltration (UF). Major functional groups and chemical structure of the isolates were identified using Fourier transform infrared spectroscopy (FT-IR) and solid-state carbon nuclear magnetic resonance (13C NMR) analysis. The influence of the isolation process on the properties of EfOM fractions was minor because the raw and reconstituted secondary effluents were found similar with respect to UV absorbance, molecular size distribution, and fluorescence character. In membrane filtration tests, unified membrane fouling index (UMFI) and hydraulic resistance were used to quantify irreversible fouling potential of different water samples. Results show that under similar DOC level in feed water, colloids present much more irreversible fouling than other fractions. The fouling effect of the isolates is related to their size, chemical properties, and solution chemistry. Further investigations have identified that the interaction between colloids and other fractions also influences the performance of colloids in fouling phenomena. © 2014 Elsevier Ltd.

  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. Studies of the fate of sulfur trioxide in coal-fired utility boilers based on modified selected condensation methods.

    Science.gov (United States)

    Cao, Yan; Zhou, Hongcang; Jiang, Wu; Chen, Chien-Wei; Pan, Wei-Ping

    2010-05-01

    The formation of sulfur trioxide (SO(3)) in coal-fired utility boilers can have negative effects on boiler performance and operation, such as fouling and corrosion of equipment, efficiency loss in the air preheater (APH), increase in stack opacity, and the formation of PM(2.5). Sulfur trioxide can also compete with mercury when bonding with injected activated carbons. Tests in a lab-scale reactor confirmed there are major interferences between fly ash and SO(3) during SO(3) sampling. A modified SO(3) procedure to maximize the elimination of measurement biases, based on the inertial-filter-sampling and the selective-condensation-collecting of SO(3), was applied in SO(3) tests in three full-scale utility boilers. For the two units burning bituminous coal, SO(3) levels starting at 20 to 25 ppmv at the inlet to the selective catalytic reduction (SCR), increased slightly across the SCR, owing to catalytic conversion of SO(2) to SO(3,) and then declined in other air pollutant control device (APCD) modules downstream to approximately 5 ppmv and 15 ppmv at the two sites, respectively. In the unit burning sub-bituminous coal, the much lower initial concentration of SO(3) estimated to be approximately 1.5 ppmv at the inlet to the SCR was reduced to about 0.8 ppmv across the SCR and to about 0.3 ppmv at the exit of the wet flue gas desulfurization (WFGD). The SO(3) removal efficiency across the WFGD scrubbers at the three sites was generally 35% or less. Reductions in SO(3) across either the APH or the dry electrostatic precipitator (ESP) in units burning high-sulfur bituminous coal were attributed to operating temperatures being below the dew point of SO(3).

  13. Energy, exergy and economic analysis of industrial boilers

    International Nuclear Information System (INIS)

    Saidur, R.; Ahamed, J.U.; Masjuki, H.H.

    2010-01-01

    In this paper, the useful concept of energy and exergy utilization is analyzed, and applied to the boiler system. Energy and exergy flows in a boiler have been shown in this paper. The energy and exergy efficiencies have been determined as well. In a boiler, the energy and exergy efficiencies are found to be 72.46% and 24.89%, respectively. A boiler energy and exergy efficiencies are compared with others work as well. It has been found that the combustion chamber is the major contributor for exergy destruction followed by heat exchanger of a boiler system. Furthermore, several energy saving measures such as use of variable speed drive in boiler's fan energy savings and heat recovery from flue gas are applied in reducing a boiler energy use. It has been found that the payback period is about 1 yr for heat recovery from a boiler flue gas. The payback period for using VSD with 19 kW motor found to be economically viable for energy savings in a boiler fan.

  14. Simulation and testing of a new condensing boiler

    International Nuclear Information System (INIS)

    Rosa, L.; Tosato, R.

    1987-01-01

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

  15. 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.

  16. Research progress of nano self - cleaning anti-fouling coatings

    Science.gov (United States)

    Liu, Y.; Zhao, Y. J.; Teng, J. L.; Wang, J. H.; Wu, L. S.; Zheng, Y. L.

    2018-01-01

    There are many methods of evaluating the performance of nano self-cleaning anti-fouling coatings, such as carbon blacking method, coating reflection coefficient method, glass microbead method, film method, contact angle and rolling angle method, organic degradation method, and the application of performance evaluation method in self-cleaning antifouling coating. For the more, the types of nano self-cleaning anti-fouling coatings based on aqueous media was described, such as photocatalytic self-cleaning coatings, silicone coatings, organic fluorine coatings, fluorosilicone coatings, fluorocarbon coatings, polysilazane self-cleaning coatings. The research and application of different kinds of nano self-cleaning antifouling coatings are anlysised, and the latest research results are summed.

  17. Worldwide genetic differentiation in the common fouling barnacle, Amphibalanus amphitrite

    KAUST Repository

    Chen, Hsi-Nien

    2014-10-21

    © 2014, © 2014 Taylor & Francis. Amphibalanus amphitrite is a common fouling barnacle distributed globally in tropical and subtropical waters. In the present study, the genetic (mitochondrial cytochrome oxidase subunit I) and morphological differentiation in A. amphitrite from 25 localities around the world were investigated. The results revealed three clades within A. amphitrite with a genetic divergence of ~ 4% among clades, whereas there were no diagnostic morphological differences among clades. Clade 1 is widely distributed in both temperate and tropical waters, whereas Clade 3 is currently restricted to the tropical region. The deep divergence among clades suggests historical isolation within A. amphitrite; thus, the present geographical overlaps are possibly a result of the combined effects of rising sea level and human-mediated dispersals. This study highlights the genetic differentiation that exists in a common, widely distributed fouling organism with great dispersal potential; future antifouling research should take into account the choice of lineages.

  18. Slagging and fouling risk of Mediterranean biomasses for combustion

    Energy Technology Data Exchange (ETDEWEB)

    Vega-Nieva, Daniel J.; Dopazo, Raquel; Ortiz, Luis (Univ. of Vigo (Spain), Forestry School, A Xunqueira Campus, Pontevedra)

    2010-07-15

    The interest in biomass combustion has grown exponentially in the last years, as a means for renewable heat and energy promoting local development and mitigating climate change. Various Mediterranean agricultural and forest resources such as olive stone, almond shell or pinecone chips remain large unutilized, despite their potential for being utilized in biomass combustion. New energy crops such as Cardoon, Brassica or Sorghum, are being introduced in Mediterranean countries for Bioenergy production; however, the slagging and fouling risk of many of these potential feedstocks are currently limiting their application in combustion processes given their high alkali, silica or chlorine contents. In this publication, various methods for biomass slagging and fouling hazard monitoring and prediction are presented based on recent studies with Mediterranean biomasses combustion in Spain

  19. A new concept for anti-fouling paint for Yachts

    DEFF Research Database (Denmark)

    Wallstroem, Eva; Jespersen, Henrik T.; Schaumburg, Kjeld

    2011-01-01

    -fouling products for yachts. To be able to reduce the amount of biocide, in this case zinc pyrithione, it is necessary to have control over the amount of biocide present in the surface layer. The control is achieved by encapsulating the biocide in a silica gel. The silica gel is dispersed together with pigments......It is shown to be possible to develop yacht paint with a reduction of 70% of biocide, without pigments/fillers (cuprous oxide and zinc oxide) that may cause long-term adverse effects in the aquatic environment, and to obtain application and usage properties that match present commercial anti...... it is encapsulated in a gel compared to a situation where it is not. This conclusion is based on the fact that the gel swells when exposed to water, and therefore the leach of zinc pyrithione is initially delayed and the biocide may start to solubilise and degrade. The result is an anti-fouling product...

  20. Fluorescence based real time monitoring of fouling in process chromatography

    Science.gov (United States)

    Pathak, Mili; Lintern, Katherine; Chopda, Viki; Bracewell, Daniel G.; Rathore, Anurag S.

    2017-01-01

    A real time monitoring of fouling in liquid chromatography has been presented. The versatility of the approach has been proven by successful implementation in three case studies with an error protein A ligand density and foulant concentration for assessing performance of protein A chromatography resin during purification of monoclonal antibodies. The observations have been supported from LC-MS/MS studies that were independently performed. The second application involves monitoring of foulant deposition during multimode cation exchange chromatography based purification of human serum albumin. Finally, in the third application, monitoring of foulants during multimodal hydrophobic interaction chromatography of recombinant human granulocyte colony stimulating factor is demonstrated. In all three cases, it is observed that the fluorescence intensity consistently increases with resin reuse as more foulants are deposited over time. The proposed approach can be readily used for real time monitoring of fouling and process control. PMID:28358349

  1. Characteristics of heat transfer fouling of thin stillage using model thin stillage and evaporator concentrates

    Science.gov (United States)

    Challa, Ravi Kumar

    The US fuel ethanol demand was 50.3 billion liters (13.3 billion gallons) in 2012. Corn ethanol was produced primarily by dry grind process. Heat transfer equipment fouling occurs during corn ethanol production and increases the operating expenses of ethanol plants. Following ethanol distillation, unfermentables are centrifuged to separate solids as wet grains and liquid fraction as thin stillage. Evaporator fouling occurs during thin stillage concentration to syrup and decreases evaporator performance. Evaporators need to be shutdown to clean the deposits from the evaporator surfaces. Scheduled and unscheduled evaporator shutdowns decrease process throughput and results in production losses. This research were aimed at investigating thin stillage fouling characteristics using an annular probe at conditions similar to an evaporator in a corn ethanol production plant. Fouling characteristics of commercial thin stillage and model thin stillage were studied as a function of bulk fluid temperature and heat transfer surface temperature. Experiments were conducted by circulating thin stillage or carbohydrate mixtures in a loop through the test section which consisted of an annular fouling probe while maintaining a constant heat flux by electrical heating and fluid flow rate. The change in fouling resistance with time was measured. Fouling curves obtained for thin stillage and concentrated thin stillage were linear with time but no induction periods were observed. Fouling rates for concentrated thin stillage were higher compared to commercial thin stillage due to the increase in solid concentration. Fouling rates for oil skimmed and unskimmed concentrated thin stillage were similar but lower than concentrated thin stillage at 10% solids concentration. Addition of post fermentation corn oil to commercial thin stillage at 0.5% increments increased the fouling rates up to 1% concentration but decreased at 1.5%. As thin stillage is composed of carbohydrates, protein, lipid

  2. In-service inspection of condenser tubes by means of electrochemical methods

    International Nuclear Information System (INIS)

    Taelemans, G.

    The commissioning of an increasing number of large nuclear power plants involves an increased significance of such condenser tube problems as: - erosion on tube ends, - generalized corrosion and pitting corrosion, - deposits in the tubes. In order to solve such problems, investigations were performed especially focused on a measurement technique that enables in-service behaviour of condenser tubes to be monitored. For such a purpose, measurement of the polarization resistance has been adopted. The existing corrosion products and scaled-off iron oxides were eliminated by means of a carborundum balls processing, as clearly appears from polarization resistance reduction. Then iron sulphate was injected in order to build a new and better protective layer. In addition, the tube was kept clean by means of foam rubber balls. There is a second implementation area: fouled condenser tubes. A significant polarization resistance reduction is noted during the acid cleaning. (orig.) [de

  3. Liquid infused porous surfaces for mineral fouling mitigation.

    Science.gov (United States)

    Charpentier, Thibaut V J; Neville, Anne; Baudin, Sophie; Smith, Margaret J; Euvrard, Myriam; Bell, Ashley; Wang, Chun; Barker, Richard

    2015-04-15

    Prevention of mineral fouling, known as scale, is a long-standing problem in a wide variety of industrial applications, such as oil production, water treatment, and many others. The build-up of inorganic scale such as calcium carbonate on surfaces and facilities is undesirable as it can result in safety risks and associated flow assurance issues. To date the overwhelming amount of research has mainly focused on chemical inhibition of scale bulk precipitation and little attention has been paid to deposition onto surfaces. The development of novel more environmentally-friendly strategies to control mineral fouling will most probably necessitate a multifunctional approach including surface engineering. In this study, we demonstrate that liquid infused porous surfaces provide an appealing strategy for surface modification to reduce mineral scale deposition. Microporous polypyrrole (PPy) coatings were fabricated onto stainless steel substrates by electrodeposition in potentiostatic mode. Subsequent infusion of low surface energy lubricants (fluorinated oil Fluorinert FC-70 and ionic liquid 1-Butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMIm)) into the porous coatings results in liquid-repellent slippery surfaces. To assess their ability to reduce surface scaling the coatings were subjected to a calcium carbonate scaling environment and the scale on the surface was quantified using Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). PPy surfaces infused with BMIm (and Fluorinert to a lesser extent) exhibit remarkable antifouling properties with the calcium carbonate deposition reduced by 18 times in comparison to untreated stainless steel. These scaling tests suggest a correlation between the stability of the liquid infused surfaces in artificial brines and fouling reduction efficiency. The current work shows the great potential of such novel coatings for the management of mineral scale fouling. Copyright © 2014 Elsevier Inc. All rights

  4. Fouling Resilient Perforated Feed Spacers for Membrane Filtration

    KAUST Repository

    Kerdi, Sarah

    2018-04-24

    The improvement of feed spacers with optimal geometry remains a key challenge for spiral-wound membrane systems in water treatment due to their impact on the hydrodynamic performance and fouling development. In this work, novel spacer designs are proposed by intrinsically modifying cylindrical filaments through perforations. Three symmetric perforated spacers (1-Hole, 2-Hole, and 3-Hole) were in-house 3D-printed and experimentally evaluated in terms of permeate flux, feed channel pressure drop and membrane fouling. Spacer performance is characterized and compared with standard no perforated (0-Hole) design under constant feed pressure and constant feed flow rate. Perforations in the spacer filaments resulted in significantly lowering the net pressure drop across the spacer filled channel. The 3-Hole spacer was found to have the lowest pressure drop (50% - 61%) compared to 0-Hole spacer for various average flow velocities. Regarding permeate flux production, the 0-Hole spacer produced 5.7 L.m-2.h-1 and 6.6 L.m-2.h-1 steady state flux for constant pressure and constant feed flow rate, respectively. The 1-Hole spacer was found to be the most efficient among the perforated spacers with 75% and 23% increase in permeate production at constant pressure and constant feed flow, respectively. Furthermore, membrane surface of 1-Hole spacer was found to be cleanest in terms of fouling, contributing to maintain higher permeate flux production. Hydrodynamic understanding of these perforated spacers is also quantified by performing Direct Numerical Simulation (DNS). The performance enhancement of these perforated spacers is attributed to the formation of micro-jets in the spacer cell that aided in producing enough unsteadiness/turbulence to clean the membrane surface and mitigate fouling phenomena. In the case of 1-Hole spacer, the unsteadiness intensity at the outlet of micro-jets and the shear stress fluctuations created inside the cells are higher than those observed with

  5. Influence of Microalgae onto submerged surfaces on Fouling

    Science.gov (United States)

    Kong, M.; Eom, C.; Yoon, B.; Yoon, H.; Kim, B.; Chung, K.

    2012-12-01

    Lots of algae together with organic matter deposited on the submerged surface can be easily observed occurring in the shallower water along the coast. This is mainly because only those organisms with the ability to adapt to the new situations created by man can firmly adhere enough to avoid being washed off. Chemical and microbiological characteristics of the fouling microalgae developed on various surfaces in contact with the seawater were made. The microbial compositions of the microalgae formed on the submerged surfaces were tested for. The quantities of the diverse microalgae in the samples developed on the prohibiting submerged surface were larger when there was no concern about materials for special selection for fouling. To confirm formation of microalgae on adsorbents was done SEM-EDS (Scanning Electron Microscope-Spectrometer) analysis. Microbial identified using optical microscope. In addition to, we quantified attaching microalgae as pass time. Experiment results, ten species which are Nitzshhia sp., Eucampia sp., Coscinodiscus sp., Licmophora sp., Rhizosolenia sp., Cylindrotheca sp., Striateela sp., Thalassionema sp., Guinardia sp., and Helicostomella sp. discovered to reservoir formed biofouling. They showed the important role microbial activity in fouling and corrosion of the surfaces in contact with the any seawater.

  6. Fouling mitigation of anion exchange membrane by zeta potential control.

    Science.gov (United States)

    Park, Jin-Soo; Lee, Hong-Joo; Choi, Seok-Ju; Geckeler, Kurt E; Cho, Jaeweon; Moon, Seung-Hyeon

    2003-03-15

    The feasibility of fouling mitigation of anion exchange membranes (AEMs) in the presence of humate was studied by adding three different types of water-soluble polymers, i.e., poly(acrylic acid) (PAA), poly(vinyl alcohol) (PVA), and poly(ethylene imine) (PEI), during electrodialysis (ED) desalination. Measurement of zeta potential of the humate used in this study showed highly negative potential (about -30 mV), implying that the humate had a strong fouling potential on the AEMs in ED. Of the three water-soluble polymers, PEI showed a positive zeta potential (about +14 mV) and is able to form an interpolymer complex with the humate. PAA and PVA hardly formed interpolymer complexes with humate due to electrostatic repulsion. The PEI-humate mixture with a volume ratio of 1:20 (PEI:humate) showed zero zeta potential, and a complexed humate with zero surface charge was formed, resulting in no fouling effects on the AEMs. Accordingly, the desalting ED experiments with PEI showed improved ED performance. Further, black colloids formed in the mixture did not cause the cell resistance to increase.

  7. DRIFT ANALYSIS ON NEURAL NETWORK MODEL OF HEAT EXCHANGER FOULING

    Directory of Open Access Journals (Sweden)

    M. RAMASAMY

    2008-04-01

    Full Text Available Neural Networks (NN provide a good platform for modeling complex and poorly understood systems in many different fields. Due to the empirical nature of NN, it is typically valid only for small operating windows. As the process drifts, the prediction accuracy of such models deteriorates very much rendering the models unfit. An on-line mechanism to follow the drift in the process is necessary in order to retrain the NN models. Information Criteria have been reported to be used for the selection of relevant input variables and determination of optimal NN model structures. This paper proposes the use of information criteria for tracking the model prediction accuracy and provides an algorithm for retraining the model. A heat exchanger in a refinery Crude Preheat Train (CPT has been used as a case study. The operational problems of heat exchangers in CPT are compounded by the varying nature of crude blends and the complex fouling phenomenon. Fouling develops slowly and therefore the drift in the process occurs on a slower scale. The performance of a NN fouling model, developed using industrial data is investigated for drift. Model performance at different operating conditions is evaluated and it has been shown that drifts do occur in the process. An algorithm for retraining NN model has been proposed.

  8. Interlaced CNT Electrodes for Bacterial Fouling Reduction of Microfiltration Membranes.

    Science.gov (United States)

    Zhang, Qiaoying; Arribas, Paula; Remillard, E Marielle; García-Payo, M Carmen; Khayet, Mohamed; Vecitis, Chad D

    2017-08-15

    Interlaced carbon nanotube electrodes (ICE) were prepared by vacuum filtering a well-dispersed carbon nanotube-Nafion solution through a laser-cut acrylic stencil onto a commercial polyvinylidene fluoride (PVDF) microfiltration (MF) membrane. Dead-end filtration was carried out using 10 7 and 10 8 CFU mL -1 Pseudomonas fluorescens to study the effects of the electrochemically active ICE on bacterial density and morphology, as well as to evaluate the bacterial fouling trend and backwash (BW) efficacy, respectively. Finally, a simplified COMSOL model of the ICE electric field was used to help elucidate the antifouling mechanism in solution. At 2 V DC and AC (total cell potential), the average bacterial log removal of the ICE-PVDF increased by ∼1 log compared to the control PVDF (3.5-4 log). Bacterial surface density was affected by the presence and polarity of DC electric potential, being 87-90% lower on the ICE cathode and 59-93% lower on the ICE anode than that on the PVDF after filtration, and BW further reduced the density on the cathode significantly. The optimal operating conditions (2 V AC) reduced the fouling rate by 75% versus the control and achieved up to 96% fouling resistance recovery (FRR) during BW at 8 V AC using 155 mM NaCl. The antifouling performance should mainly be due to electrokinetic effects, and the electric field simulation by COMSOL model suggested electrophoresis and dielectrophoresis as likely mechanisms.

  9. Fouling Issues in Membrane Bioreactors (MBRs for Wastewater Treatment: Major Mechanisms, Prevention and Control Strategies

    Directory of Open Access Journals (Sweden)

    Petros K. Gkotsis

    2014-10-01

    Full Text Available Membrane fouling is one of the most important considerations in the design and operation of membrane systems as it affects pretreatment needs, cleaning requirements, operating conditions, cost and performance. Given that membrane fouling represents the main limitation to membrane process operation, it is unsurprising that the majority of membrane material and process research and development conducted is dedicated to its characterization and amelioration. This work presents the fundamentals of fouling issues in membrane separations, with specific regard to membrane fouling in Membrane Bioreactors (MBRs and the most frequently applied preventive-control strategies. Feed pretreatment, physical and chemical cleaning protocols, optimal operation of MBR process and membrane surface modification are presented and discussed in detail. Membrane fouling is the major obstacle to the widespread application of the MBR technology and, therefore, fouling preventive-control strategies is a hot issue that strongly concerns not only the scientific community, but industry as well.

  10. Deposit Formation during Coal-Straw Co-Combustion in a Utility PF-Boiler

    DEFF Research Database (Denmark)

    Andersen, Karin Hedebo

    1998-01-01

    formation was experienced to increase·the major part of the K from the straw is bonded as K-Al-silicate in the ash·the only K-salt of significance in the deposits is K2SO4.The major straw-induced change of importance for operation and corrosion is thus related to the increased content of K2SO4......This Ph.D. thesis reports the research on ash deposit formation in the convective pass of a utility PF-boiler during co-combustion of coal and straw. The work was based on experimental results from a two-year full scale demonstration programme at the Studstrup Power Station, Unit 1 (MKS1), owned......, where both deposit amount and tenacity increased compared to COCERR. From these results, the formation of possibly problematic upstream fouling deposits during coal-straw co-combustion is expected to occur primarily in the first pass.Based on the SEM analyses, the upstream probe deposits collected from...

  11. Detailed investigation of Cl-corrosion initiated by deposits formed in biomass-fired boilers. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Frandsen, Flemming J.; Lith, S. van

    2009-10-15

    The aim was to investigate deposit-induced Cl-corrosion under well-controlled laboratory conditions, simulating the conditions in biomass-fired boilers. This has been done by exposing pieces of superheater tubes, covered by synthetic salts, at temperatures and gas mixtures simulating biomass-fired conditions. The corroded specimens have been studied in detail using a Scanning Electron Microscope (SEM), in order to determine the corrosion rate, and to investigate the chemistry and morphology of the corrosive attack. The project has been divided into four activities: A1: Relationship between the Cl-concentration in the deposit, and the corrosion rate. A2: Influence of cation type (K+ and Na+) on the mobility of Cl in the deposit. A3: Influence of metal temperature on the corrosion rate. A4: Critical evaluation of the existing experience for minimizing corrosion in full-scale boilers firing totally or partly with biomass. (LN)

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    A number of full-scale deposit probe measuring campaigns conducted in grate-fired and suspension-fired boilers, fired with biomass, have been reviewed and compared. The influence of operational parameters on the chemistry of ash and deposits, on deposit build-up rates, and on shedding behavior has...... of the deposits formed is determined by the fly ash composition and the flue gas temperature; increases in the local flue gas temperature lead to higher contents of Si and Ca and lower contents of Cl in the deposits. The net deposit build-up rates in grate-fired and suspension-fired boilers are at similar levels......, 0–100 g/m2·h, while the ash deposit propensity is an order of magnitude larger in grate fired boilers than in suspension-fired boilers. Deposit build-up rates were found to increase at flue gas temperatures close to the melting temperatures of the fly ash. Furthermore, the rate of deposit build...

  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.

  14. 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.

  15. Understanding the risk of scaling and fouling in hollow fiber forward osmosis membrane application

    KAUST Repository

    Majeed, Tahir

    2016-06-23

    Fouling studies of forward osmosis (FO) were mostly conducted based on fouling evaluation principals applied to pressure membrane processes such as reverse osmosis (RO)/nanofiltration (NF)/microfiltration (MF)/ultrafiltration (UF). For RO/NF/MF/UF processes, the single flux driving force (hydraulic pressure) remains constant, thus the fouling effect is easily evaluated by comparing flux data with the baseline. Whilst, the scenario of fouling effects for FO process is entirely different from RO/NF/MF/UF processes. Continuously changing driving force (osmotic pressure difference), the changes in concentration polarization associated with the varying draw solution/feed solution concentration and the fouling layer effects collectively influence the FO flux. Thus, usual comparison of the FO flux outcome with the baseline results can not exactly indicate the real affect of membrane fouling, rather presents a misleading cumulative effect. This study compares the existing FO fouling technique with an alternate fouling evaluation approach using two FO set-ups. Scaling and fouling risk for hollow fiber FO was separately investigated using synthetic water samples and model organic foulants as alginate, humic acid and bovine serum albumin. Results indicated that FO flux declines up to 5% and 49% in active layer-feed solution and active layer-draw solution orientations respectively.

  16. Membrane Bioreactor (MBR Technology for Wastewater Treatment and Reclamation: Membrane Fouling

    Directory of Open Access Journals (Sweden)

    Oliver Terna Iorhemen

    2016-06-01

    Full Text Available The membrane bioreactor (MBR has emerged as an efficient compact technology for municipal and industrial wastewater treatment. The major drawback impeding wider application of MBRs is membrane fouling, which significantly reduces membrane performance and lifespan, resulting in a significant increase in maintenance and operating costs. Finding sustainable membrane fouling mitigation strategies in MBRs has been one of the main concerns over the last two decades. This paper provides an overview of membrane fouling and studies conducted to identify mitigating strategies for fouling in MBRs. Classes of foulants, including biofoulants, organic foulants and inorganic foulants, as well as factors influencing membrane fouling are outlined. Recent research attempts on fouling control, including addition of coagulants and adsorbents, combination of aerobic granulation with MBRs, introduction of granular materials with air scouring in the MBR tank, and quorum quenching are presented. The addition of coagulants and adsorbents shows a significant membrane fouling reduction, but further research is needed to establish optimum dosages of the various coagulants/adsorbents. Similarly, the integration of aerobic granulation with MBRs, which targets biofoulants and organic foulants, shows outstanding filtration performance and a significant reduction in fouling rate, as well as excellent nutrients removal. However, further research is needed on the enhancement of long-term granule integrity. Quorum quenching also offers a strong potential for fouling control, but pilot-scale testing is required to explore the feasibility of full-scale application.

  17. Membrane Bioreactor (MBR) Technology for Wastewater Treatment and Reclamation: Membrane Fouling.

    Science.gov (United States)

    Iorhemen, Oliver Terna; Hamza, Rania Ahmed; Tay, Joo Hwa

    2016-06-15

    The membrane bioreactor (MBR) has emerged as an efficient compact technology for municipal and industrial wastewater treatment. The major drawback impeding wider application of MBRs is membrane fouling, which significantly reduces membrane performance and lifespan, resulting in a significant increase in maintenance and operating costs. Finding sustainable membrane fouling mitigation strategies in MBRs has been one of the main concerns over the last two decades. This paper provides an overview of membrane fouling and studies conducted to identify mitigating strategies for fouling in MBRs. Classes of foulants, including biofoulants, organic foulants and inorganic foulants, as well as factors influencing membrane fouling are outlined. Recent research attempts on fouling control, including addition of coagulants and adsorbents, combination of aerobic granulation with MBRs, introduction of granular materials with air scouring in the MBR tank, and quorum quenching are presented. The addition of coagulants and adsorbents shows a significant membrane fouling reduction, but further research is needed to establish optimum dosages of the various coagulants/adsorbents. Similarly, the integration of aerobic granulation with MBRs, which targets biofoulants and organic foulants, shows outstanding filtration performance and a significant reduction in fouling rate, as well as excellent nutrients removal. However, further research is needed on the enhancement of long-term granule integrity. Quorum quenching also offers a strong potential for fouling control, but pilot-scale testing is required to explore the feasibility of full-scale application.

  18. Assessment of Silt Density Index (SDI) as Fouling Propensity Parameter in Reverse Osmosis Desalination

    KAUST Repository

    Rachman, Rinaldi

    2011-07-01

    Reverse osmosis operations are facing persistent fouling phenomenon that has challenged the integrity of these processes. Prediction of fouling potential by measuring a fouling index toward feed water is essential to ensure robust operation. Moreover, employing a reliable fouling index with good reproducibility and precision is necessary. Silt density index (SDI) is considered insufficient in terms of reliability and empirical theory, among other limitations. Nevertheless due its simplicity, SDI measurement is utilized extensively in RO desalination systems. The aim of this research is to assess the reliability of SDI. Methods include the investigation of different SDI membranes and study of the nature of the SDI filtration. Results demonstrate the existence of the membrane properties\\' variation within manufacturers, which then causes a lack of accuracy in fouling risk estimation. The nature of particles during SDI filtration provides information that particle concentration and size play a significant role on SDI quantification with substantial representation given by particles with size close to membrane nominal pore size. Moreover, turbidity assisted SDI measurements along with determination of UF pretreated and clean water fouling potential, establishes the indication of non-fouling related phenomena involved on SDI measurement such as a natural organic matter adsorption and hydrodynamic condition that alters during filtration. Additionally, it was found that the latter affects the sensitivity of SDI by being represented by some portions of SDI value. Keywords: Reverse Osmosis, Fouling index, Particulate Fouling, Silt Density Index (SDI), and Assessment of SDI.

  19. Ammonia recovery from agricultural wastes by membrane distillation: fouling characterization and mechanism.

    Science.gov (United States)

    Zarebska, A; Nieto, D Romero; Christensen, K V; Norddahl, B

    2014-06-01

    One of the main obstacles impeding implementation of membrane distillation for the recovery and concentration of ammonia from swine manure is wetting caused by fouling. Due to the different types of fouling which can occur in a membrane system, foulants characterization is a complex problem. To elucidate the fouling mechanism, deposit morphology and composition of foulants have been determined using Scanning Electron Microscopy, X-ray Energy Dispersive Spectrometry, Attenuated Total Reflectance Infrared Spectrometry, Ion chromatography and Inductively coupled plasma-optical emission spectroscopy. Based on the analysis of fouled membranes, it is concluded that membrane fouling is dominated by organic fouling in combination with deposits of inorganic elements and microorganisms. After a week of running the membrane process without cleaning, the average fouling layer thickness was estimated to 10-15 μm. The fouling layer further results in a loss of membrane hydrophobicity. This indicates that fouling could be a severe problem for membrane distillation performance. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. FOULING CHARACTERIZATION OF MEMBRANE CONTACTORS USED FOR THE RECOVERY AND CONCENTRATION OF AMMONIA FROM UNDIGESTED PIG SLURRY

    DEFF Research Database (Denmark)

    Zarebska, Agata; Norddahl, Birgir; Christensen, Knud Villy

    2012-01-01

    to the different types of fouling which can occur in a membrane system, characterization of fouling is a complex problem. Fouling intensity, morphology and composition of fouling layers has been determined using Scanning Electron Microscopy, X-ray Energy Dispersive Spectrometry and Attenuated Total Reflectance......The main obstacle impeding implementation of membrane contactors for the recovery and concentration of ammonia from swine manure is the phenomena of membrane fouling. Fouling is defined as the accumulation of suspended or dissolved substances on the membrane surface and/or within its pores. Due...

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

    International Nuclear Information System (INIS)

    Gadzhanov, P.

    1997-01-01

    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 194 o C. 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 (165 o C) provides both combustion and ecological benefits

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

    African Journals Online (AJOL)

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

  3. Assessment of Some Performance Characteristics of Refuse Boiler ...

    African Journals Online (AJOL)

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

  4. 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...

  5. Test of a small domestic boiler using different pellets

    International Nuclear Information System (INIS)

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

    2004-01-01

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

  6. 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.

  7. 46 CFR 56.50-30 - Boiler feed piping.

    Science.gov (United States)

    2010-10-01

    ... boiler. (c) Feed water regulators, heaters, and grease extractors. (1) Where feed water regulators, tubular feed water heaters, and grease extractors are installed, an alternate means of operation with... least two separate means of supplying feed water for the boilers. All feed pumps shall be fitted with...

  8. 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.

  9. 30 CFR 77.411 - Compressed air and boilers; general.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Compressed air and boilers; general. 77.411 Section 77.411 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE... COAL MINES Safeguards for Mechanical Equipment § 77.411 Compressed air and boilers; general. All...

  10. Boiler inspection manipulator for Torness Power Station

    International Nuclear Information System (INIS)

    Carrey, R.T.A.; Playle, M.J.

    1996-01-01

    In-service inspection at Torness Advanced Gas-cooled Reactor is achieved, via penetrations above and below the core area and boilers and through eight circulator penetrations for inspection of the sub-diagrid area. A manipulator is described which can access the area above the reactor core via any of these eight peripheral penetrations. The design and fabrication of the manipulator has led to innovation with a number of possible solutions being tendered. In reactor deployment of the successful design is expected in early 1997. (UK)

  11. Qualification of stainless steel for OTEC heat exchanger tubes

    Energy Technology Data Exchange (ETDEWEB)

    LaQue, F.L.

    1979-01-01

    The history of the AL-6X alloy is reviewed and its credentials as a candidate for use as tubing in Ocean Thermal Energy Conversion Heat Exchangers are examined. Qualification is based on results of accelerated tests using ferric chloride for resistance to crevice corrosion and pitting, long-time crevice corrosion and pitting tests in natural sea water and anticipated resistance to attack by ammonia and mixtures of ammonia and sea water. Since the alloy has no natural resistance to fouling by marine organisms, it must be able to accomodate action to prevent fouling by chlorination or to remove it by mechanical cleaning techniques or appropriate chemical cleaning methods. The satisfactory behavior indicated by the various accelerated and long-time corrosion tests has been confirmed by excellent performance of several million feet of tubing in condensers in coastal power plants. Early evaluation tests demonstrated the need for proper heat treatment to avoid the presence of a sigma phase, which promoted severe pitting of some, but not all, specimens in tests in natural sea water. The available data qualify the AL-6X alloy as being a satisfactory alternate to titanium for tubes in OTEC heat exchangers.

  12. Boiling process modelling peculiarities analysis of the vacuum boiler

    Science.gov (United States)

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

    2017-06-01

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

  13. A study of burning processes of fossil fuels in straitened conditions of furnaces in low capacity boilers by an example of natural gas

    Science.gov (United States)

    Roslyakov, P. V.; Proskurin, Y. V.; Khokhlov, D. A.; Zaichenko, M. N.

    2018-03-01

    The aim of this work is to research operations of modern combined low-emission swirl burner with a capacity of 2.2 MW for fire-tube boiler type KV-GM-2.0, to ensure the effective burning of natural gas, crude oil and diesel fuel. For this purpose, a computer model of the burner and furnace chamber has been developed. The paper presents the results of numerical investigations of the burner operation, using the example of natural gas in a working load range from 40 to 100%. The basic features of processes of fuel burning in the cramped conditions of the flame tube have been identified to fundamentally differ from similar processes in the furnaces of steam boilers. The influence of the design of burners and their operating modes on incomplete combustion of fuel and the formation of nitrogen oxides has been determined.

  14. Establishing an energy efficiency recommendation for commercial boilers

    International Nuclear Information System (INIS)

    Ware, Michelle J.

    2000-01-01

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

  15. Establishing an energy efficiency recommendation for commercial boilers

    Energy Technology Data Exchange (ETDEWEB)

    Ware, Michelle J.

    2000-08-01

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

  16. 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 ...

  17. Eustachian tube patency

    Science.gov (United States)

    Eustachian tube patency refers to how much the eustachian tube is open. The eustachian tube runs between the middle ear and the throat. It controls the pressure behind the eardrum and middle ear space. This helps keep ...

  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

    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.

  19. 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.

  20. '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.

  1. 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.

  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

    2005-01-31

    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.

  3. Code boiler and pressure vessel life assessment

    International Nuclear Information System (INIS)

    Farr, J.R.

    1992-01-01

    In the United States of America and in Canada, laws and controls for determining life assessment for continued operation of equipment exist only for those pressure vessels built to Section III and evaluated according to Section XI. In this presentation, some of those considerations which are made in the USA and Canada for deciding on life or condition assessment of boilers and pressure vessels designed and constructed to other sections of the ASME Boiler and Pressure Vessel Code are reviewed. Life assessment or condition assesssment is essential in determining what is necessary for continued operation. With no ASME rules being adopted by laws or regulations, other than OSHA in the USA and similar environmental controls in Canada, to control life assessment for continued operation, the equipment owner must decide if assessment is to be done and how much to do. Some of those considerations are reviewed along with methods and procedures to make an assessment along with a discussion of where the ASME B and PV Code currently stands regarding continued operation. (orig.)

  4. 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.

  5. Fouling of Seawater Reverse Osmosis (SWRO) Membrane: Chemical and Microbiological Characterization

    KAUST Repository

    Khan, Muhammad T.

    2013-12-01

    In spite of abundant water resources, world is suffering from the scarcity of usable water. Seawater Reverse Osmosis (SWRO) desalination technology using polymeric membranes has been recognized as a key solution to water scarcity problem. However, economic sustainability of this advanced technology is adversely impacted by the membrane fouling problem. Fouling of RO membranes is a highly studied phenomenon. However, literature is found to be lacking a detailed study on kinetic and dynamic aspects of SWRO membrane fouling. The factors that impact the fouling dynamics, i.e., pretreatment and water quality were also not adequately studied at full–scale of operation. Our experimental protocol was designed to systematically explore these fouling aspects with the objective to improve the understanding of SWRO membrane fouling mechanisms. An approach with multiple analytical techniques was developed for fouling characterization. In addition to the fouling layer characterization, feed water quality was also analysed to assess its fouling potential. Study of SWRO membrane fouling dynamics and kinetics revealed variations in relative abundance of chemical and microbial constituents of the fouling layer, over operating time. Aromatic substances, most likely humic–like substances, were observed at relatively high abundance in the initial fouling layer, followed by progressive increase in relative abundances of proteins and polysaccharides. Microbial population grown on all membranes was dominated by specific groups/species belonging to different classes of Proteobacteria phylum; however, similar to abiotic foulant, their relative abundance also changed with the biofilm age and with the position of membrane element in RO vessel. Our results demonstrated that source water quality can significantly impact the RO membrane fouling scenarios. Moreover, the major role of chlorination in the SWRO membrane fouling was highlighted. It was found that intermittent mode of chlorination

  6. Application of electrochemical processes to membrane bioreactors for improving nutrient removal and fouling control.

    Science.gov (United States)

    Borea, Laura; Naddeo, Vincenzo; Belgiorno, Vincenzo

    2017-01-01

    Membrane bioreactor (MBR) technology is becoming increasingly popular as wastewater treatment due to the unique advantages it offers. However, membrane fouling is being given a great deal of attention so as to improve the performance of this type of technology. Recent studies have proven that the application of electrochemical processes to MBR represents a promising technological approach for membrane fouling control. In this work, two intermittent voltage gradients of 1 and 3 V/cm were applied between two cylindrical perforated electrodes, immersed around a membrane module, at laboratory scale with the aim of investigating the treatment performance and membrane fouling formation. For comparison purposes, the reactor also operated as a conventional MBR. Mechanisms of nutrient removal were studied and membrane fouling formation evaluated in terms of transmembrane pressure variation over time and sludge relative hydrophobicity. Furthermore, the impact of electrochemical processes on transparent exopolymeric particles (TEP), proposed as a new membrane fouling precursor, was investigated in addition to conventional fouling precursors such as bound extracellular polymeric substances (bEPS) and soluble microbial products (SMP). All the results indicate that the integration of electrochemical processes into a MBR has the advantage of improving the treatment performance especially in terms of nutrient removal, with an enhancement of orthophosphate (PO 4 -P) and ammonia nitrogen (NH 4 -N) removal efficiencies up to 96.06 and 69.34 %, respectively. A reduction of membrane fouling was also observed with an increase of floc hydrophobicity to 71.72 %, a decrease of membrane fouling precursor concentrations, and, thus, of membrane fouling rates up to 54.33 %. The relationship found between TEP concentration and membrane fouling rate after the application of electrochemical processes confirms the applicability of this parameter as a new membrane fouling indicator.

  7. Corrosion of metals and alloys - Corrosion and fouling in industrial cooling water systems - Part 1: Guidelines for conducting pilot-scale evaluation of corrosion and fouling control additives for open recirculating cooling water systems

    CERN Document Server

    International Organization for Standardization. Geneva

    2006-01-01

    Corrosion of metals and alloys - Corrosion and fouling in industrial cooling water systems - Part 1: Guidelines for conducting pilot-scale evaluation of corrosion and fouling control additives for open recirculating cooling water systems

  8. Heat exchanger tube mounts

    Science.gov (United States)

    Wolowodiuk, W.; Anelli, J.; Dawson, B.E.

    1974-01-01

    A heat exchanger in which tubes are secured to a tube sheet by internal bore welding is described. The tubes may be moved into place in preparation for welding with comparatively little trouble. A number of segmented tube support plates are provided which allow a considerable portion of each of the tubes to be moved laterally after the end thereof has been positioned in preparation for internal bore welding to the tube sheet. (auth)

  9. 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)

    Ferreira, V.C.

    1985-01-01

    During the inspection of a power station boiler was find out a high amount of scale/deposits on the tubes surface (> 100 mg/cm 2 ). 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) [pt

  10. Tube holding system

    International Nuclear Information System (INIS)

    Cunningham, R.C.

    1978-01-01

    A tube holding rig is described for the lateral support of tubes arranged in tight parcels in a heat exchanger. This tube holding rig includes not less than two tube supporting assemblies, with a space between them, located crosswise with respect to the tubes, each supporting assembly comprising a first set of parallel components in contact with the tubes, whilst a second set of components is also in contact with the tubes. These two sets of parts together define apertures through which the tubes pass [fr

  11. Research and development to overcome fouling of membranes. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Narang, S.C.; Sharma, S.K.; Hum, G.; Ventura, S.C.; Roberts, D.L.; Gottschlich, D.; Ahner, N.

    1998-11-01

    To overcome fouling of membranes, SRI International is developing a unique piezoelectric backing for ultrafiltration membranes. This backing is capable of producing local turbulence next to the membrane to minimize concentration polarization and the rate of buildup of solutes and particulate matter on the membrane surface. We have studied piezoelectrically assisted ultrafiltration in more detail, with the objective to apply this process to industrial ultrafiltrations. We conducted several ultrafiltration experiments on flat sheet membranes with model dextran solutions and with electrocoat paint to study flux enhancement as a function of parameters such as feed flow rate, feed pressure, as well as the piezodriver-membrane system.

  12. Fundamentals of membrane bioreactors materials, systems and membrane fouling

    CERN Document Server

    Ladewig, Bradley

    2017-01-01

    This book provides a critical, carefully researched, up-to-date summary of membranes for membrane bioreactors. It presents a comprehensive and self-contained outline of the fundamentals of membrane bioreactors, especially their relevance as an advanced water treatment technology. This outline helps to bring the technology to the readers’ attention, and positions the critical topic of membrane fouling as one of the key impediments to its more widescale adoption. The target readership includes researchers and industrial practitioners with an interest in membrane bioreactors.

  13. SHIP HULL FOULING AS A MEANS OF MAKROZOOBENTHOS DISPERSAL

    Directory of Open Access Journals (Sweden)

    Joanna Cupak

    2014-10-01

    Full Text Available Hulls of 9 boats operating in inland waterways and coastal Baltic waters along were examined for the presence of fouling organisms. A total of 23 animal taxa were recorded, 8 of them being alien species known to have been earlier introduced into the Baltic Sea basin. The most frequent taxa were: Amphibalanus improvisus, Chironomidae, Dreissena polymorpha, and Gammarus tigrinus. The fi ndings of this study clearly demonstrate the important role potentially played by small crafts in the introduction and spread of alien species not only in the River Odra estuary, but also in the coastal Baltic waters outside of the Odra plume.

  14. Fouling in a MBR system with rotating membrane discs

    DEFF Research Database (Denmark)

    Jørgensen, Mads Koustrup; Bentzen, Thomas Ruby; Christensen, Morten Lykkegaard

    Membrane bioreactors (MBR) are an attractive alternative solution for municipal and industrial wastewater treatment. The MBR, which is a combination of a bioreactor for sludge degradation and a membrane for separation, has the advantages of a low footprint, ability to handle high sludge...... to conventionally activated sludge systems. Therefore, it is essential to understand the impact of enhanced shear on filtration performance. The influence of shear and sludge concentration on the limiting flux is investigated using the limiting flux as a measure of the degree of fouling. The utilized MBR system...

  15. 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.

  16. 9 CFR 91.22 - Protection from heat of boilers and engines.

    Science.gov (United States)

    2010-01-01

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

  17. 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 classification...

  18. 30 CFR 57.13001 - General requirements for boilers and pressure vessels.

    Science.gov (United States)

    2010-07-01

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

  19. 40 CFR 63.7506 - Do any boilers or process heaters have limited requirements?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 13 2010-07-01 2010-07-01 false Do any boilers or process heaters have..., and Institutional Boilers and Process Heaters General Compliance Requirements § 63.7506 Do any boilers or process heaters have limited requirements? (a) New or reconstructed boilers and process heaters in...

  20. 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 of...

  1. 49 CFR 230.20 - Alteration and repair report for steam locomotive boilers.

    Science.gov (United States)

    2010-10-01

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

  2. 46 CFR 61.05-5 - Preparation of boilers for inspection and test.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Preparation of boilers for inspection and test. 61.05-5... PERIODIC TESTS AND INSPECTIONS Tests and Inspections of Boilers § 61.05-5 Preparation of boilers for... preparing the boilers for the hydrostatic test, they shall be filled with water at not less than 70 °F. and...

  3. 40 CFR 63.7491 - Are any boilers or process heaters not subject to this subpart?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 13 2010-07-01 2010-07-01 false Are any boilers or process heaters not..., and Institutional Boilers and Process Heaters What This Subpart Covers § 63.7491 Are any boilers or process heaters not subject to this subpart? The types of boilers and process heaters listed in paragraphs...

  4. 40 CFR 63.7499 - What are the subcategories of boilers and process heaters?

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 13 2010-07-01 2010-07-01 false What are the subcategories of boilers..., and Institutional Boilers and Process Heaters Emission Limits and Work Practice Standards § 63.7499 What are the subcategories of boilers and process heaters? The subcategories of boilers and process...

  5. 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 referring...

  6. 30 CFR 56.13001 - General requirements for boilers and pressure vessels.

    Science.gov (United States)

    2010-07-01

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

  7. Silt density index and modified fouling index relation, and effect of pressure, temperature and membrane resistance

    NARCIS (Netherlands)

    Al-Hadidi, A.M.M.; Alhadidi, A.; Kemperman, Antonius J.B.; Blankert, B.; Blankert, B.; Schippers, J.C.; Wessling, Matthias; van der Meer, Walterus Gijsbertus Joseph

    2011-01-01

    Particulate matter present in feed water of reverse osmosis and nanofiltration membrane elements tends to deposit on the membrane surface and spacers. This type of fouling results in permeate flux decline, loss of product quality and membrane damage. To characterize the fouling potential of RO feed

  8. Fouling behavior of silica nanoparticle-surfactant mixtures during constant flux dead-end ultrafiltration

    NARCIS (Netherlands)

    Trzaskus, Krzystof; Lee, Sooi Li; de Vos, Wiebe Matthijs; Kemperman, Antonius J.B.; Nijmeijer, Kitty

    2017-01-01

    The increasing use of engineered nanoparticles in customer products results in their accumulation in water sources. In this experimental study, we investigated the role of surfactant type (cationic, anionic and non-ionic) and concentration on fouling development, nanoparticle rejection and fouling

  9. Costs and benefits to European shipping of ballast-water and hull-fouling treatment

    NARCIS (Netherlands)

    Fernandes, Jose A.; Santos, Lionel; Vance, Thomas; Fileman, Tim; Smith, David; Bishop, John D.D.; Viard, Frédérique; Queirós, Ana M.; Merino, Gorka; Buisman, Erik; Austen, Melanie C.

    2016-01-01

    Maritime transport and shipping are impacted negatively by biofouling, which can result in increased fuel consumption. Thus, costs for fouling reduction can be considered an investment to reduce fuel consumption. Anti-fouling measures also reduce the rate of introduction of non-indigenous species

  10. Contribution of different effluent organic matter fractions to membrane fouling in ultrafiltration of treated domestic wastewater

    KAUST Repository

    Zheng, Xing

    2012-12-01

    In the present work, effluent organic matter (EfOM) in treated domestic wastewater was separated into hydrophobic neutrals, colloids, hydrophobic acids, transphilic acids and neutrals and hydrophilic compounds. Their contribution to dissolved organic carbon (DOC) was identified. Further characterization was conducted with respect to molecular size and hydrophobicity. Each isolated fraction was dosed into salt solution to identify its fouling potential in ultrafiltration (UF) using a hydrophilized polyethersulfone membrane. The results show that each kind of EfOM leads to irreversible fouling. At similar delivered DOC load to the membrane, colloids present the highest fouling effect in terms of both reversible and irreversible fouling. The hydrophobic organics show much lower reversibility than the biopolymers present. However, as they are of much smaller size than the membrane pore opening, they cannot lead to such severe fouling as biopolymers do. In all of the isolated fractions, hydrophilics show the lowest fouling potential. For either colloids or hydrophobic substances, increasing their content in feedwater leads to worse fouling. The co-effect between biopolymers and other EfOM fractions has also been identified as one of the mechanisms contributing to UF fouling in filtering EfOM-containing waters. © IWA Publishing 2012.

  11. Particulate and organic matter fouling of SWRO systems: Characterization, modelling and applications

    NARCIS (Netherlands)

    Salinas Rodríguez, S.G.

    2011-01-01

    Particulate/colloidal and organic fouling in seawater reverse osmosis (SWRO) systems results in flux decline, higher energy costs, increased salt passage, increased cleaning frequency, and use of chemicals. In practice, indices like SDI and MFI are used to assess particulate fouling, but they are

  12. Particulate and organic matter fouling of seawater reverse osmosis systems : Characterization, modelling and applications

    NARCIS (Netherlands)

    Salinas Rodriguez, S.G.

    2011-01-01

    Particulate/colloidal and organic fouling in seawater reverse osmosis (SWRO) systems results in flux decline, higher energy costs, increased salt passage, increased cleaning frequency, and use of chemicals. In practice, indices like SDI and MFI are used to assess particulate fouling, but they are

  13. Workshop on an Assessment of Gas-Side Fouling in Fossil Fuel Exhaust Environments

    Science.gov (United States)

    Marner, W. J. (Editor); Webb, R. L. (Editor)

    1982-01-01

    The state of the art of gas side fouling in fossil fuel exhaust environments was assessed. Heat recovery applications were emphasized. The deleterious effects of gas side fouling including increased energy consumption, increased material losses, and loss of production were identified.

  14. Ultrasonic Reflectometry for Monitoring the Effect of Pressure on Sludge Fouling of MF Membranes

    DEFF Research Database (Denmark)

    Jørgensen, Mads Koustrup; Kujundzic, Elmira; Greenberg, Alan

    Membrane fouling remains the key limitation for the widespread use of membrane bioreactors (MBR) for wastewater treatment. This constraint has led to an increasing number of studies that examine the influence of various operational parameters and physicochemical properties on fouling layer...

  15. Studies on fouling diatoms from the Zuari Estuary, Goa (west coast of India)

    Digital Repository Service at National Institute of Oceanography (India)

    Redekar, P.D.; Wagh, A.B.

    Very few studies are available in density of fouling diatoms from Zuari estuary, Goa, India. Hence this work was undertaken. In all 49 species of fouling diatoms belonging to 19 genera were recorded on glass slide as panels at 1 m depth in Zuari...

  16. Up-date on cyclone combustion and cyclone boilers

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-07-01

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

  17. 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.

  18. Cross connecting absorber module inlets of multiple boiler units

    International Nuclear Information System (INIS)

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

    1991-01-01

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

  19. A novel direct-fired porous-medium boiler

    Science.gov (United States)

    Prasartkaew, Boonrit

    2018-01-01

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

  20. Evaluation of conditions of SNCR in small boilers

    International Nuclear Information System (INIS)

    Kullendorff, A.; Lorentzon, K.

    1996-04-01

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