WorldWideScience

Sample records for boiler process model

  1. 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.

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

    International Nuclear Information System (INIS)

    Filkoski, Risto V.

    2004-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Belošević Srđan V.

    2016-01-01

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

  4. 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...

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

    DEFF Research Database (Denmark)

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

    2014-01-01

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

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  7. 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.

  8. Structured Mathematical Modeling of Industrial Boiler

    Directory of Open Access Journals (Sweden)

    Abdullah Nur Aziz

    2014-04-01

    Full Text Available As a major utility system in industry, boilers consume a large portion of the total energy and costs. Significant reduction of boiler cost operation can be gained through improvements in efficiency. In accomplishing such a goal, an adequate dynamic model that comprehensively reflects boiler characteristics is required. This paper outlines the idea of developing a mathematical model of a water-tube industrial boiler based on first principles guided by the bond graph method in its derivation. The model describes the temperature dynamics of the boiler subsystems such as economizer, steam drum, desuperheater, and superheater. The mathematical model was examined using industrial boiler performance test data.It can be used to build a boiler simulator or help operators run a boiler effectively.

  9. Structured Mathematical Modeling of Industrial Boiler

    OpenAIRE

    Aziz, Abdullah Nur; Nazaruddin, Yul Yunazwin; Siregar, Parsaulian; Bindar, Yazid

    2014-01-01

    As a major utility system in industry, boilers consume a large portion of the total energy and costs. Significant reduction of boiler cost operation can be gained through improvements in efficiency. In accomplishing such a goal, an adequate dynamic model that comprehensively reflects boiler characteristics is required. This paper outlines the idea of developing a mathematical model of a water-tube industrial boiler based on first principles guided by the bond graph method in its derivation. T...

  10. MODELLING, SIMULATING AND OPTIMIZING BOILERS

    DEFF Research Database (Denmark)

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

    2003-01-01

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

  11. 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

    1998-12-31

    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

  12. 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

  13. Model-free adaptive control of supercritical circulating fluidized-bed boilers

    Science.gov (United States)

    Cheng, George Shu-Xing; Mulkey, Steven L

    2014-12-16

    A novel 3-Input-3-Output (3.times.3) Fuel-Air Ratio Model-Free Adaptive (MFA) controller is introduced, which can effectively control key process variables including Bed Temperature, Excess O2, and Furnace Negative Pressure of combustion processes of advanced boilers. A novel 7-input-7-output (7.times.7) MFA control system is also described for controlling a combined 3-Input-3-Output (3.times.3) process of Boiler-Turbine-Generator (BTG) units and a 5.times.5 CFB combustion process of advanced boilers. Those boilers include Circulating Fluidized-Bed (CFB) Boilers and Once-Through Supercritical Circulating Fluidized-Bed (OTSC CFB) Boilers.

  14. Model-based Control of a Bottom Fired Marine Boiler

    DEFF Research Database (Denmark)

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

    2005-01-01

    This paper focuses on applying model based MIMO control to minimize variations in water level for a specific boiler type. A first principles model is put up. The model is linearized and an LQG controller is designed. Furthermore the benefit of using a steam °ow measurement is compared to a strategy...... relying on estimates of the disturbance. Preliminary tests at the boiler system show that the designed controller is able to control the boiler process. Furthermore it can be concluded that relying on estimates of the steam flow in the control strategy does not decrease the controller performance...

  15. Model-based Control of a Bottom Fired Marine Boiler

    DEFF Research Database (Denmark)

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

    This paper focuses on applying model based MIMO control to minimize variations in water level for a specific boiler type. A first principles model is put up. The model is linearized and an LQG controller is designed. Furthermore the benefit of using a steam °ow measurement is compared to a strategy...... relying on estimates of the disturbance. Preliminary tests at the boiler system show that the designed controller is able to control the boiler process. Furthermore it can be concluded that relying on estimates of the steam flow in the control strategy does not decrease the controller performance...

  16. 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...

  17. 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

  18. 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....

  19. 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.)

  20. 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)

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

    DEFF Research Database (Denmark)

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

    2003-01-01

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

  2. CFD modeling of a boiler's tubes rupture

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  3. 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...

  4. 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...

  5. 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.

  6. NOx PREDICTION FOR FBC BOILERS USING EMPIRICAL MODELS

    Directory of Open Access Journals (Sweden)

    Jiří Štefanica

    2014-02-01

    Full Text Available Reliable prediction of NOx emissions can provide useful information for boiler design and fuel selection. Recently used kinetic prediction models for FBC boilers are overly complex and require large computing capacity. Even so, there are many uncertainties in the case of FBC boilers. An empirical modeling approach for NOx prediction has been used exclusively for PCC boilers. No reference is available for modifying this method for FBC conditions. This paper presents possible advantages of empirical modeling based prediction of NOx emissions for FBC boilers, together with a discussion of its limitations. Empirical models are reviewed, and are applied to operation data from FBC boilers used for combusting Czech lignite coal or coal-biomass mixtures. Modifications to the model are proposed in accordance with theoretical knowledge and prediction accuracy.

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

    NARCIS (Netherlands)

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

    2010-01-01

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

  8. 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...

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

    Directory of Open Access Journals (Sweden)

    Chunlin Wang

    2017-01-01

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

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

    DEFF Research Database (Denmark)

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

    1997-01-01

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

  11. 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...

  12. Investigation of fuel lean reburning process in a 1.5 MW boiler

    International Nuclear Information System (INIS)

    Kim, Hak Young; Baek, Seung Wook; Kim, Se Won

    2012-01-01

    Highlights: → We examine a detailed study of fuel lean reburning process in a 1.5 MW gas-fired boiler. → Experimental and numerical researches are conducted. → We investigate change in the level of NO X and CO emission. → The recirculation flow is important in the fuel lean reburning process. -- Abstract: This paper examines a detailed study of fuel lean reburning process applied to a 1.5 MW gas-fired boiler. Experimental and numerical studies were carried out to investigate the effect of the fuel lean reburning process on the NO X reduction and CO emission. Natural gas (CH 4 ) was used as the reburn as well as the main fuel. The amount of the reburn fuel, injection location and thermal load of boiler were considered as experimental parameters. The flue gas data revealed that the fuel lean reburning process led to NO X reduction up to 43%, while CO emission was limited to less than 30 ppm for the 100% thermal load condition. The commercial computational fluid dynamics code FLUENT 6.3, which included turbulence, chemical reaction, radiation and NO modeling, was used to predict the fluid flow and heat transfer characteristics under various operational conditions in the boiler. Subsequently, predicted results were validated with available measured data such as gas temperature distributions and local mean NO X concentrations. The detailed numerical results showed that the recirculation flow developed inside the boiler was found to play an important role in improving the effectiveness of fuel lean reburning process.

  13. Model technique for aerodynamic study of boiler furnace

    Energy Technology Data Exchange (ETDEWEB)

    1966-02-01

    The help of the Division was recently sought to improve the heat transfer and reduce the exit gas temperature in a pulverized-fuel-fired boiler at an Australian power station. One approach adopted was to construct from Perspex a 1:20 scale cold-air model of the boiler furnace and to use a flow-visualization technique to study the aerodynamic patterns established when air was introduced through the p.f. burners of the model. The work established good correlations between the behaviour of the model and of the boiler furnace.

  14. 40 CFR 65.149 - Boilers and process heaters.

    Science.gov (United States)

    2010-07-01

    ... stream is not introduced as or with the primary fuel, a temperature monitoring device in the fire box...-throughput transfer racks, as applicable, shall meet the requirements of this section. (2) The vent stream... thermal units per hour) or greater. (ii) A boiler or process heater into which the vent stream is...

  15. Seismic model of the nuclear boiler SPX2

    International Nuclear Information System (INIS)

    Christodoulou, K.

    1982-01-01

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

  16. 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

  17. Procesoptimerende multivariable regulatorer til kraftværkskedler. Process Optimizing Multivariable Controllers for Powerplant Boilers

    DEFF Research Database (Denmark)

    Hansen, T.

    The purpose of this Ph.D. thesis is twofold: The first purpose is to devise a new method for application of multivariable controllers in boiler control systems in which they act as optional process optimizing extensions to conventional control systems and in such a way that the safety measures...... mentioned, the concept is applicable to new as well as existing plants. The seccond purpose is to suggest specific methods for experimental modelling and multivariable controller design which are possible to use under the conceptual framework, implement them and test them in a boiler application....

  18. Modelling of a one pass smoke tube boiler

    DEFF Research Database (Denmark)

    Karstensen, Claus M. S.; Sørensen, Kim

    2004-01-01

    A nonlinear state-space model with five states describing a one pass smoke tube boiler has been formulated. By means of mass- and energy-balance the model describes the dynamics of the Furnace, the Convection Zone and the Water/Steam Part and the three sub models are merged into an overall model....... The model is further linearized for use in a linear control design. The simulations have been carried out by means of MATLAB/SIMULINK and the models have been verified with measurements from a full scale boiler plant. Parameters in the model that are difficult to calculate have been estimated and the method...

  19. 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

  20. 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.

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

    Directory of Open Access Journals (Sweden)

    Żymełka Piotr

    2017-12-01

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

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

    Science.gov (United States)

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

    2017-11-01

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

  3. 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

  4. An alternative process to treat boiler feed water for reuse.

    Science.gov (United States)

    Guirgis, Adel; Ghosh, Jyoti P; Achari, Gopal; Langford, Cooper H; Banerjee, Daliya

    2012-09-01

    A bench-scale process to treat boiler feed water for reuse in steam generation was developed. Industrial water samples from a steam-assisted gravity drainage plant in northern Alberta, Canada, were obtained and samples characterized. The technology, which consists of coagulation-settling to remove oil/grease and particulates followed by an advanced oxidative treatment, led to clean water samples with negligible organic carbon. Coagulation followed by settling removed most particulates and some insoluble organics. The advanced oxidative treatment removed any remaining color in the samples, decreased the organic content to near-zero, and provided water ready for reuse.

  5. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Persson, Tomas; Fiedler, Frank; Nordlander, Svante

    2006-05-15

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

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

    Directory of Open Access Journals (Sweden)

    Zhenhao Tang

    2017-01-01

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

  8. Analysis of selected problems of biomass combustion process in batch boilers - experimental and numerical approach

    Science.gov (United States)

    Szubel, Mateusz

    2016-03-01

    It is possible to list numerous groups of heating units that are used in households, such as boilers, stoves and units used as supporting heat sources, namely fireplaces. In each case, however, the same operational problems may be evoked [1]. To understand the causes of energy losses in a boiler system, a proper definition of significant elements of the unit's heat balance is necessary. In the group of energy losses, the flue gas loss and the incomplete combustion loss are the most significant factors. The problem with the loss resulting from incomplete combustion, which is related to the presence of combustible substances in the exhaust, is especially significant in case of biomass boilers [2, 3]. The paper presents results of the research and the optimisation of the biomass combustion process in the 180 kW batch boiler. The studies described have been focused on the reduction of the pollutants emission, which was primarily realised by the modifications of the air feeding system. Results of the experiments and the CFD simulations have been compared and discussed. Both in case of the model as well as the experiment, positive influence of the modifications on the emission have been observed.

  9. Analysis of selected problems of biomass combustion process in batch boilers - experimental and numerical approach

    Directory of Open Access Journals (Sweden)

    Szubel Mateusz

    2016-01-01

    Full Text Available It is possible to list numerous groups of heating units that are used in households, such as boilers, stoves and units used as supporting heat sources, namely fireplaces. In each case, however, the same operational problems may be evoked [1]. To understand the causes of energy losses in a boiler system, a proper definition of significant elements of the unit’s heat balance is necessary. In the group of energy losses, the flue gas loss and the incomplete combustion loss are the most significant factors. The problem with the loss resulting from incomplete combustion, which is related to the presence of combustible substances in the exhaust, is especially significant in case of biomass boilers [2, 3]. The paper presents results of the research and the optimisation of the biomass combustion process in the 180 kW batch boiler. The studies described have been focused on the reduction of the pollutants emission, which was primarily realised by the modifications of the air feeding system. Results of the experiments and the CFD simulations have been compared and discussed. Both in case of the model as well as the experiment, positive influence of the modifications on the emission have been observed.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-10-01

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

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

    DEFF Research Database (Denmark)

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

    1998-01-01

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

  12. FLAME MONITORING IN POWER STATION BOILERS USING IMAGE PROCESSING

    Directory of Open Access Journals (Sweden)

    K. Sujatha

    2012-05-01

    Full Text Available Combustion quality in power station boilers plays an important role in minimizing the flue gas emissions. In the present work various intelligent schemes to infer the flue gas emissions by monitoring the flame colour at the furnace of the boiler are proposed here. Flame image monitoring involves capturing the flame video over a period of time with the measurement of various parameters like Carbon dioxide (CO2, excess oxygen (O2, Nitrogen dioxide (NOx, Sulphur dioxide (SOx and Carbon monoxide (CO emissions plus the flame temperature at the core of the fire ball, air/fuel ratio and the combustion quality. Higher the quality of combustion less will be the flue gases at the exhaust. The flame video was captured using an infrared camera. The flame video is then split up into the frames for further analysis. The video splitter is used for progressive extraction of the flame images from the video. The images of the flame are then pre-processed to reduce noise. The conventional classification and clustering techniques include the Euclidean distance classifier (L2 norm classifier. The intelligent classifier includes the Radial Basis Function Network (RBF, Back Propagation Algorithm (BPA and parallel architecture with RBF and BPA (PRBFBPA. The results of the validation are supported with the above mentioned performance measures whose values are in the optimal range. The values of the temperatures, combustion quality, SOx, NOx, CO, CO2 concentrations, air and fuel supplied corresponding to the images were obtained thereby indicating the necessary control action taken to increase or decrease the air supply so as to ensure complete combustion. In this work, by continuously monitoring the flame images, combustion quality was inferred (complete/partial/incomplete combustion and the air/fuel ratio can be automatically varied. Moreover in the existing set-up, measurements like NOx, CO and CO2 are inferred from the samples that are collected periodically or by

  13. CFD modeling of a boiler's tubes rupture

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-12-15

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

  14. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

  16. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-07-01

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

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

    International Nuclear Information System (INIS)

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

    1997-01-01

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

  19. Investigations of combustion process in combined cooker-boiler fired on solid fuels

    Directory of Open Access Journals (Sweden)

    Stojiljković Dragoslava D.

    2006-01-01

    Full Text Available The aim of the investigation was to make some reconstructions on the existing stove used for cooking and baking and to obtain the combined cooker-boiler which will fulfill the demands of European standard EN 12815. Implementation of modern scientific achievements in the field of combustion on stoves and furnaces fired on solid fuels was used. During the investigations four various constructions were made with different fresh air inlet and secondary air supply with the intention to obtain more complete combustion with increased efficiency and reduced CO emission. Three different fuels were used: firewood, coal, and wood briquette. A numerous parameters were measured: fuel weight changes during the combustion process, temperature of inlet and outlet water, flue gas composition (O2, CO, SO2, CO2, NOx, flue gas temperature, ash quantity etc. The result of the investigations is the stove with the efficiency of more than 75% - boiler Class 1 (according EN 12815 and CO emission of about 1% v/v. The results obtained during the measurements were used as parameters for modeling of combustion process. .

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

    Science.gov (United States)

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

    2017-02-01

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

  1. Modelling of thermal behaviour of iron oxide layers on boiler tubes

    Science.gov (United States)

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

    2016-05-01

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

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

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

    NARCIS (Netherlands)

    Satyavada, H.; Baldi, S.

    2016-01-01

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

  4. 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 ...

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

    Directory of Open Access Journals (Sweden)

    Aleksejs Jurenoks

    2017-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Lovmand Hvid, S.

    2011-12-15

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

  7. Physical characterization of biomass fuels prepared for suspension firing in utility boilers for CFD modelling

    DEFF Research Database (Denmark)

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

    2007-01-01

    A sample of 1.2 kg Danish wheat straw (Jutland, 1997) prepared for suspension firing in a PF boiler has been analyzed for the purpose of generating size and shape distribution functions applicable to numerical modelling of combustion processes involving biomass, characterised by highly anisotropic...... shapes. The sample is subdivided by straw type, and coherent size, type and mass distribution parameters are reported for the entire sample. This type of data is necessary in order to use CFD reliably as a design and retrofit tool for co-firing biomass with fossil fuels, as the combustion processes...

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

    Directory of Open Access Journals (Sweden)

    Orlova K.Y.

    2017-01-01

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

  9. Mathematical modelling of a steam boiler room to research thermal efficiency

    International Nuclear Information System (INIS)

    Bujak, J.

    2008-01-01

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

  10. Numerical modelling of a straw-fired grate boiler

    DEFF Research Database (Denmark)

    Kær, Søren Knudsen

    2004-01-01

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

  11. Numerical modelling of a straw-fired grate boiler

    DEFF Research Database (Denmark)

    Kær, Søren Knudsen

    2004-01-01

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

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

    International Nuclear Information System (INIS)

    Chu Yuntao; Lou Chun; Cheng Qiang; Zhou Huaichun

    2008-01-01

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

  13. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-07-01

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

  15. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    A. Vikhansky; E. Bar-Ziv; B. Chudnovsky; A. Talanker; E. Eddings; A. Sarofim [Ben-Gurion University of the Negev, Beer-Sheva (Israel). Department of Biotechnology and Environmental Engineering

    2004-04-01

    A three-dimensional computational fluid dynamics code was used to analyse the performance of 550MW pulverized coal combustion opposite a wall-fired boiler (of the Israel Electric Corporation (IEC)) at different operation modes. The main objective of this study was to prove that connecting plant measurements with three-dimensional furnace modelling is a cost-effective method for design, optimization and problem solving in power plant operation. Heat flux results from calculations were compared with measurements in the boiler and showed good agreement. Consequently, the code was used to study hydrodynamic aspects of air-flue gases mixing in the upper part of the boiler. It was demonstrated that effective mixing between flue gases and overfire air is of essential importance for CO reburning. From the complementary experimental-numerical effort, IEC considers a possibility to improve the boiler performance by replacing the existing OFA nozzles by those with higher penetration depth of the air jets, with the aim to ensure proper mixing to achieve better CO reburning. 7 refs., 7 figs., 1 tab.

  18. Prediction method of unburnt carbon for coal fired utility boiler using image processing technique of combustion flame

    International Nuclear Information System (INIS)

    Shimoda, M.; Sugano, A.; Kimura, T.; Watanabe, Y.; Ishiyama, K.

    1990-01-01

    This paper reports on a method predicting unburnt carbon in a coal fired utility boiler developed using an image processing technique. The method consists of an image processing unit and a furnace model unit. temperature distribution of combustion flames can be obtained through the former unit. The later calculates dynamics of the carbon reduction from the burner stages to the furnace outlet using coal feed rate, air flow rate, chemical and ash content of coal. An experimental study shows that the prediction error of the unburnt carbon can be reduced to 10%

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Meyer-Kahrweg, H

    1978-10-19

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, J R

    1996-05-01

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

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

    International Nuclear Information System (INIS)

    Zhang, Fan; Wu, Xiao; Shen, Jiong

    2017-01-01

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

  3. Effect of kind of solid fuel onto noxious compound emissions in the firing up process of a low output water boiler

    International Nuclear Information System (INIS)

    Wilk, R.; Szymczyk, J.; Zielinski, Z.; Wystemp, E.

    1992-01-01

    NO x , SO 2 , CO and polynuclear aromatic hydrocarbon emission tests were carried out during the firing up process of a low output boiler for three kinds of smokeless solid fuels and boiler coal. It has been stated that the use of low emissive fuels in low output boilers did not protect against noxious compound emissions during firing up the boiler. (author). 13 refs, 8 figs, 4 tabs

  4. Cogeneration Technology Alternatives Study (CTAS). Volume 6: Computer data. Part 2: Residual-fired nocogeneration process boiler

    Science.gov (United States)

    Knightly, W. F.

    1980-01-01

    Computer generated data on the performance of the cogeneration energy conversion system are presented. Performance parameters included fuel consumption and savings, capital costs, economics, and emissions of residual fired process boilers.

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

    International Nuclear Information System (INIS)

    Kljajić, Miroslav; Gvozdenac, Dušan; Vukmirović, Srdjan

    2012-01-01

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

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

    DEFF Research Database (Denmark)

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

    2008-01-01

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

  7. Black liquor combustion validated recovery boiler modeling, five-year report

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-08-01

    The objective of this project was to develop 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 project originated in October 1990 and was scheduled to run for four years. At that time, there was considerable emphasis on developing accurate predictions of the physical carryover of macroscopic particles of partially burnt black liquor and smelt droplets out of the furnace, since this was seen as the main cause of boiler plugging. This placed a major emphasis on gas flow patterns within the furnace and on the mass loss rates and swelling and shrinking rates of burning black liquor drops. As work proceeded on developing the recovery boiler furnace model, it became apparent that some recovery boilers encounter serious plugging problems even when physical carryover was minimal. After the original four-year period was completed, the project was extended to address this issue. The objective of the extended project was to improve the utility of the models by including the black liquor chemistry relevant to air emissions predictions and aerosol formation, and by developing the knowledge base and computational tools to relate furnace model outputs to fouling and plugging of the convective sections of the boilers. The work done to date includes CFD model development and validation, acquisition of information on black liquor combustion fundamentals and development of improved burning models, char bed model development, and model application and simplification.

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

    DEFF Research Database (Denmark)

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

    2007-01-01

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

  9. Technical and economic feasibility of alternative fuel use in process heaters and small boilers

    Energy Technology Data Exchange (ETDEWEB)

    1980-02-01

    The technical and economic feasibility of using alternate fuels - fuels other than oil and natural gas - in combustors not regulated by the Powerplant and Industrial Fuel Use Act of 1978 (FUA) was evaluated. FUA requires coal or alternate fuel use in most large new boilers and in some existing boilers. Section 747 of FUA authorizes a study of the potential for reduced oil and gas use in combustors not subject to the act: small industrial boilers with capacities less than 100 MMBtu/hr, and process heat applications. Alternative fuel use in combustors not regulated by FUA was examined and the impact of several measures to encourage the substitution of alternative fuels in these combustors was analyzed. The primary processes in which significant fuel savings can be achieved are identified. Since feedstock uses of oil and natural gas are considered raw materials, not fuels, feedstock applications are not examined in this analysis. The combustors evaluated in this study comprise approximately 45% of the fuel demand projected in 1990. These uses would account for more than 3.5 million barrels per day equivalent fuel demand in 1990.

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

    Directory of Open Access Journals (Sweden)

    Balicki Adrian

    2014-06-01

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

  11. Low Load Model of a Once-through Boiler with Recirculation

    DEFF Research Database (Denmark)

    Trangbæk, Klaus

    2006-01-01

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

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  13. 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...

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

    DEFF Research Database (Denmark)

    Rajh, Boštjan; Yin, Chungen; Samec, Niko

    2016-01-01

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

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

    Science.gov (United States)

    2012-07-01

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

  16. Feasibility of applying coal-fired boiler technology to process heaters

    Energy Technology Data Exchange (ETDEWEB)

    O' Sullivan, T F

    1978-01-01

    The preponderance of coal in US fossil fuel reserves has raised the question of the conversion of hydrocarbon process heaters to coal firing. A review undertaken in 1977 by an API sub-committee concluded that neither existing heaters nor existing heater designs were capable of modification or revision to burn coal, and that new coal-fired design consistent with process requirements would be needed for this purpose. In recognition of this need a cooperative investigation was undertaken by Combustion Engineering and Lummus. The present paper, reporting on this investigation, reviews existing coal-fired boiler equipment and techniques and describes their adaptation to the development of a design concept for a coal-fired process heater. To this end, the design parameters for both steam boilers and fired heaters have been compared and have been incorporated into a workable coal-fired process heater design which includes the following features; a coutant bottom for ash removal, an ash-hopper located under both radiant and convection chambers, a tangent type finned wall construction, a straight through gas flow pattern, a vertical tube convection section, horizontal firing using round burners, and an overall geometry allowing a coil arrangement capable of accommodating varying numbers of parallel serpentine coils. These features are integrated into a conceptual heater design which is detailed in a series of illustrations.

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

    International Nuclear Information System (INIS)

    Chaney, Joel; Liu Hao; Li Jinxing

    2012-01-01

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

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

    Science.gov (United States)

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

    2018-05-25

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

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

    Directory of Open Access Journals (Sweden)

    Sreepradha Chandrasekharan

    2017-06-01

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

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

    Science.gov (United States)

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

    2017-06-01

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

  1. Gas fired boilers: Perspective for near future fuel composition and impact on burner design process

    Science.gov (United States)

    Schiro, Fabio; Stoppato, Anna; Benato, Alberto

    2017-11-01

    The advancements on gas boiler technology run in parallel with the growth of renewable energy production. The renewable production will impact on the fuel gas quality, since the gas grid will face an increasing injection of alternative fuels (biogas, biomethane, hydrogen). Biogas allows producing energy with a lower CO2 impact; hydrogen production by electrolysis can mitigate the issues related to the mismatch between energy production by renewable and energy request. These technologies will contribute to achieve the renewable production targets, but the impact on whole fuel gas production-to-consumption chain must be evaluated. In the first part of this study, the Authors present the future scenario of the grid gas composition and the implications on gas fed appliances. Given that the widely used premixed burners are currently designed mainly by trial and error, a broader fuel gas quality range means an additional hitch on this design process. A better understanding and structuring of this process is helpful for future appliance-oriented developments. The Authors present an experimental activity on a premixed condensing boiler setup. A test protocol highlighting the burners' flexibility in terms of mixture composition is adopted and the system fuel flexibility is characterized around multiple reference conditions.

  2. Gas fired boilers: Perspective for near future fuel composition and impact on burner design process

    Directory of Open Access Journals (Sweden)

    Schiro Fabio

    2017-01-01

    Full Text Available The advancements on gas boiler technology run in parallel with the growth of renewable energy production. The renewable production will impact on the fuel gas quality, since the gas grid will face an increasing injection of alternative fuels (biogas, biomethane, hydrogen. Biogas allows producing energy with a lower CO2 impact; hydrogen production by electrolysis can mitigate the issues related to the mismatch between energy production by renewable and energy request. These technologies will contribute to achieve the renewable production targets, but the impact on whole fuel gas production-to-consumption chain must be evaluated. In the first part of this study, the Authors present the future scenario of the grid gas composition and the implications on gas fed appliances. Given that the widely used premixed burners are currently designed mainly by trial and error, a broader fuel gas quality range means an additional hitch on this design process. A better understanding and structuring of this process is helpful for future appliance-oriented developments. The Authors present an experimental activity on a premixed condensing boiler setup. A test protocol highlighting the burners' flexibility in terms of mixture composition is adopted and the system fuel flexibility is characterized around multiple reference conditions.

  3. Considerations on the question of applying ion exchange or reverse osmosis methods in boiler feedwater processing

    International Nuclear Information System (INIS)

    Marquardt, K.; Dengler, H.

    1976-01-01

    This consideration is to show that the method of reverse osmosis presents in many cases an interesting and economical alternative to part and total desolination plants using ion exchangers. The essential advantages of the reverse osmosis are a higher degree of automization, no additional salting of the removed waste water, small constructional volume of the plant as well as favourable operational costs with increasing salt content of the crude water to be processed. As there is a relatively high salt breakthrough compared to the ion exchange method, the future tendency in boiler feedwater processing will be more towards a combination of methods of reverse osmosis and post-purification through continuous ion exchange methods. (orig./LH) [de

  4. 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.

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

    Science.gov (United States)

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

    2014-02-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-05-15

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

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

    DEFF Research Database (Denmark)

    Saastamoinen, Jaakko; Aho, Martti; Moilanen, Antero

    2010-01-01

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

  8. 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

  9. 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.

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

    Directory of Open Access Journals (Sweden)

    Palash Sarkar

    2017-02-01

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

  11. 40 CFR Table 2 to Subpart Ddddd of... - Operating Limits for Boilers and Process Heaters With Particulate Matter Emission Limits

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 13 2010-07-01 2010-07-01 false Operating Limits for Boilers and Process Heaters With Particulate Matter Emission Limits 2 Table 2 to Subpart DDDDD of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION...

  12. 40 CFR Table 4 to Subpart Ddddd of... - Operating Limits for Boilers and Process Heaters With Hydrogen Chloride Emission Limits

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 13 2010-07-01 2010-07-01 false Operating Limits for Boilers and Process Heaters With Hydrogen Chloride Emission Limits 4 Table 4 to Subpart DDDDD of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS...

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

    Science.gov (United States)

    Duo, Wenli; Leclerc, Denys

    2007-04-01

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

  14. Physical and combustion characteristics of biomass particles prepared by different milling processes for suspension firing in utility boilers

    DEFF Research Database (Denmark)

    Yin, Chungen; Momenikouchaksaraei, Maryam; Kær, Søren Knudsen

    2016-01-01

    close to suspension-fired boilers. The ignition, devolatilization and burnout times of the milled particles under different combustion conditions are analysed. A one-dimensional transient model, properly accounting for the particle-ambient flow interaction and appropriately addressing the key sub...

  15. OPTIMIZATION OF TRANSIEN PROCESSES OF WATER LEVEL VARIATION IN DRUM OF STEAM BOILERS

    Directory of Open Access Journals (Sweden)

    G. T. Kulakov

    2014-01-01

    Full Text Available The work of regulator in general three-impulse automatic control system of water level in drum of boiler doesn’t supply quality of internal and external disturbance attack (presentation of regulation mistakes. That is why it is needed to improve. Different methods of proportional plus reset controller regulation of three-phase automatic feed control system are considered. There were suggested new methods to improve the quality of regulation of water level in boilers. Here the step system of automatic regulation was determined, on the base of transfer function.It is noticed that optimal transient processes supply calculation of numerical value of transmission factor of regulator at g =2,618, it is more then was recommended, but statistic mistakes remain. The transient simulation method in fast-time scale is recommended, this allow to determine early the value of statistic mistake of regulation by disturbances of reheated steam consumption and properly change the task to compensating device of step automatic control system. And numerical value of time constant criteria  should be calculated on the base of numbers of golden section(Phi, taking into account the definite time constant of lead section and time-lag, time-lag on controlled influence channel, and also taking into account maximum value of controlled influence. This method allow to reduce in two times the total time of regulation, to decrease absolute mistake of regulation in three times, and maximum value of regulation influence by feedwater in 1,7 times.

  16. 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.

  17. Predictive ability of boiler production models | Ogundu | Animal ...

    African Journals Online (AJOL)

    The weekly body weight measurements of a growing strain of Ross broiler were used to compare the of ability of three mathematical models (the multi, linear, quadratic and Exponential) to predict 8 week body weight from early body measurements at weeks I, II, III, IV, V, VI and VII. The results suggest that the three models ...

  18. Modelling of boiler heating surfaces and evaporator circuits

    DEFF Research Database (Denmark)

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

    2002-01-01

    the circulation in the evaporator circuit. The models have been developed as Differential-Algebraic-Equations (DAE) and MATLAB has been applied for the integration of the models. In general MATLAB has proved to be very stable for the relatively stiff equation systems. Experimental verification is planned...

  19. Development of METHANE de-NOX Reburn Process for Wood Waste and Biomass Fired Stoker Boilers - Final Report - METHANE de-NOX Reburn Technology Manual

    Energy Technology Data Exchange (ETDEWEB)

    J. Rabovitser; B. Bryan; S. Wohadlo; S. Nester; J. Vaught; M. Tartan (Gas Technology Institute); R. Glickert (ESA Environmental Solutions)

    2007-12-31

    The overall objective of this project was to demonstrate the effectiveness of the METHANE de-NOX® (MdN) Reburn process in the Forest Products Industry (FPI) to provide more efficient use of wood and sludge waste (biosolids) combustion for both energy generation and emissions reduction (specifically from nitrogen oxides (NOx)) and to promote the transfer of the technology to the wide range of wood waste-fired stoker boilers populating the FPI. This document, MdN Reburn Commercial Technology Manual, was prepared to be a resource to promote technology transfer and commercialization activities of MdN in the industry and to assist potential users understand its application and installation requirements. The Manual includes a compilation of MdN commercial design data from four different stoker boiler designs that were baseline tested as part of the development effort. Design information in the Manual include boiler CFD model studies, process design protocols, engineering data sheets and commercial installation drawings. Each design package is unique and implemented in a manner to meet specific mill requirements.

  20. Experimental investigation of N2O formation in selective non-catalytic NOx reduction processes performed in stoker boiler

    Directory of Open Access Journals (Sweden)

    Krawczyk Piotr

    2016-12-01

    Full Text Available Stoker fired boiler plants are common throughout Eastern Europe. Increasingly strict emission standards will require application of secondary NOx abatement systems on such boilers. Yet operation of such systems, in addition to reducing NOx emissions, may also lead to emission of undesirable substances, for example N2O. This paper presents results of experimental tests concerning N2O formation in the selective non-catalytic NOx emission reduction process (SNCR in a stoker boiler (WR 25 type. Obtained results lead to an unambiguous conclusion that there is a dependency between the NOx and N2O concentrations in the exhaust gas when SNCR process is carried out in a coal-fired stoker boiler. Fulfilling new emission standards in the analysed equipment will require 40–50% reduction of NOx concentration. It should be expected that in such a case the N2O emission will be approximately 55–60 mg/m3, with the NOx to N2O conversion factor of about 40%.

  1. 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

  2. CREATION OF OPTIMIZATION MODEL OF STEAM BOILER RECUPERATIVE AIR HEATER

    Directory of Open Access Journals (Sweden)

    N. B. Carnickiy

    2006-01-01

    Full Text Available The paper proposes to use a mathematical modeling as one of the ways intended to improve quality of recuperative air heater design (RAH without significant additional costs, connected with the change of design materials or fuel type. The described conceptual mathematical AHP optimization model of RAH consists of optimized and constant parameters, technical limitations and optimality criteria.The paper considers a methodology for search of design and regime parameters of an air heater which is based on the methods of multi-criteria optimization. Conclusions for expediency of the given approach usage are made in the paper.

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

    Directory of Open Access Journals (Sweden)

    Petr Trávníček

    2011-01-01

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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-06-01

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

  6. 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,...

  7. Thermalhydraulic assessment of the Pickering NGS 'B' feed and bleed system for the hot boiler chemical clean (Siemens Process)

    International Nuclear Information System (INIS)

    Lorencez, Carlos M.

    2000-01-01

    The Hot Boiler Chemical Clean (HBCC) process from Siemens, to be used in PNGS, requires that the Heat Transport System (HTS) temperature be maintained in the range 160 to 170 o C for several days. To achieve these thermalhydraulic condition, the core decay power and the pump power of the main circulating pumps in a 3-3 configuration are employed to warm up the HTS from approximately 38 o C to 170 o C. At this point, high Bleed bias is applied to the signal of the HTS pressure controller to provide high Feed and Bleed flows, which are used to control the HTS temperature by means of the Bleed Cooler. To address any concern posed by these infrequently used HTS thermalhydraulic conditions, a detailed thermalhydraulic model of the Feed and Bleed System, that also includes the Gland Supply, Gland Return and Purification systems, was developed for the TUF code to determine the suitability of the Feed and Bleed System to conduct the HBCC. The model was then used to estimate the parameters such as Feed and Bleed flows, valve openings, pressure and temperature distributions throughout the Feed and Bleed System required for the application of HBCC. (author)

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

    International Nuclear Information System (INIS)

    Gruber, Thomas; Scharler, Robert; Obernberger, Ingwald

    2015-01-01

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

  9. A novel least squares support vector machine ensemble model for NOx emission prediction of a coal-fired boiler

    International Nuclear Information System (INIS)

    Lv, You; Liu, Jizhen; Yang, Tingting; Zeng, Deliang

    2013-01-01

    Real operation data of power plants are inclined to be concentrated in some local areas because of the operators’ habits and control system design. In this paper, a novel least squares support vector machine (LSSVM)-based ensemble learning paradigm is proposed to predict NO x emission of a coal-fired boiler using real operation data. In view of the plant data characteristics, a soft fuzzy c-means cluster algorithm is proposed to decompose the original data and guarantee the diversity of individual learners. Subsequently the base LSSVM is trained in each individual subset to solve the subtask. Finally, partial least squares (PLS) is applied as the combination strategy to eliminate the collinear and redundant information of the base learners. Considering that the fuzzy membership also has an effect on the ensemble output, the membership degree is added as one of the variables of the combiner. The single LSSVM and other ensemble models using different decomposition and combination strategies are also established to make a comparison. The result shows that the new soft FCM-LSSVM-PLS ensemble method can predict NO x emission accurately. Besides, because of the divide and conquer frame, the total time consumed in the searching the parameters and training also decreases evidently. - Highlights: • A novel LSSVM ensemble model to predict NO x emissions is presented. • LSSVM is used as the base learner and PLS is employed as the combiner. • The model is applied to process data from a 660 MW coal-fired boiler. • The generalization ability of the model is enhanced. • The time consuming in training and searching the parameters decreases sharply

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

    DEFF Research Database (Denmark)

    Solberg, Brian; Andersen, Palle; Maciejowski, Jan

    2008-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-11-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-07-01

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

  13. 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.

  14. Advanced process control for solid fuel boilers. Phase 2; Avancerad processtyrning av fastbraensleeldade rostpannor. Etapp 2

    Energy Technology Data Exchange (ETDEWEB)

    Ehleskog, Rickard; Lundborg, Rickard; Schuster, Robert; Wrangensten, Lars [AaF-Energikonsult AB, Stockholm (Sweden)

    2002-04-01

    AaF-Energikonsult AB runs within the research programme 'Applied combustion technology' a bigger project under the title 'Possibilities to improved operation of forest-industrial bark boilers by optimised combustion control'. In the project several measures have been identified, that can help to improve the conditions favourable for the combustion and fluid dynamic, for four selected reference grate boilers and grate boilers in general. The boiler at Billerud's paper mill, which is underlying to this project in several ways, is now being rebuilt. During the modifications of the boiler the existing control system will be modified with modern technique to enable operation with low emissions. The new control system consists of several parts, of witch the IR-based ones for fuel input and grate feeding are two totally separated systems. The pressure of the dome, i.e. the effect of the boiler, is the most superior parameter, and is regulated with the combustion air. Amounts of secondary and tertiary air are quoted to the total combustion airflow. The primary oxygen level is primarily regulated with the tertiary air. But if this won't be done without the tertiary air to diverge from de defined working area, the secondary air will assist. The oxygen set point is constantly decreasing until the CO-level exceeds a defined level. Then, the set point will be momentary increased. CFD-calculations have been performed for the modified boiler in Karlsborg for two different loads. The simulations clearly show that the flue gases have a more even retention time in the modified boiler and that the flow pattern is significantly improved. However, concentration gradients of oxygen and temperature gradients still exist. The conclusion is that there is a potential for further improving of the air and flue gas control strategies. The following new control strategies are proposed in the project based on conventional analyse technology; If the furnace

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

    NARCIS (Netherlands)

    Satyavada, Harish; Baldi, S.

    2018-01-01

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

  16. HR boiler

    Energy Technology Data Exchange (ETDEWEB)

    1982-08-01

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

  17. Gas fired boilers: Perspective for near future fuel composition and impact on burner design process

    OpenAIRE

    Schiro Fabio; Stoppato Anna; Benato Alberto

    2017-01-01

    The advancements on gas boiler technology run in parallel with the growth of renewable energy production. The renewable production will impact on the fuel gas quality, since the gas grid will face an increasing injection of alternative fuels (biogas, biomethane, hydrogen). Biogas allows producing energy with a lower CO2 impact; hydrogen production by electrolysis can mitigate the issues related to the mismatch between energy production by renewable and energy request. These technologies will ...

  18. Analysis of Flue Gas Desulfurization (FGD) Processes for Potential Use on Army Coal-Fired Boilers

    Science.gov (United States)

    1980-09-01

    SYSTEMS ALKALI- LIME/LIMESTONE AMMONIA SCRUBBING LIME OR LIMESTONE HC SCRUBBER INJECTION DRY SYSTEMS NAHCOLITE INJECTION BOILER INJECTION...requirements, and flexibility. Single-alkali flue gas scrubbers are gas-Hquid contacting devices that use the chemical reactions between soluble alkali... scrubbers are gas-liquid contacting devices that use the chemical reactions between limestone (mostly CaC03) and SOp to remove the oxides of sulfur from

  19. Optimization of a lignite-fired open pulverizing system boiler process based on variations in the drying agent composition

    International Nuclear Information System (INIS)

    Ma, Youfu; Zhang, Hua; Yuan, Yichao; Wang, Zhiyun

    2015-01-01

    This paper evaluates three lignite-fired OPSB (open pulverizing system boiler) processes, named OPSB-A, OPSB-B and OPSB-C, corresponding to three options of drying agents used for the pulverizing systems. OPSB-B is similar to our previous work [18] on drying agent composition. Performances of the three OPSBs were calculated and compared with a 600 MW lignite-fired boiler as the reference. The results showed that the coal savings of OPSB-A and OPSB-C were 5.41% and 4.06% in comparison with the reference boiler, whereas for OPSB-B, the savings was 2.57%. Accordingly, emissions of each OPSB could be reduced in proportion to the coal savings. Among the three OPSBs, OPSB-C showed the best performance of water recovery from mill-exhausts because it had the highest mill-exhaust water dew point of 73.2 °C, whereas the exhaust dew points of OPSB-A and OPSB-B were 63.9 °C and 70.9 °C, respectively. Both OPSB-C and OPSB-B are beneficial for achieving a high mill-exhaust humidity ratio, which facilitates water recovery from the mill-exhaust, and a low oxygen content in mill-exhaust, which improves the operating safety of the pulverizing systems, whereas OPSB-A is relatively inferior in these respects. The OPSB-C process is recommended for engineering applications because of its favorable overall performances. - Highlights: • Three lignite-fired OPSB processes are analyzed based on a conventional 600 MW boiler. • OPSB-A, OPSB-B and OPSB-C show coal savings of 5.41%, 2.57 and 4.06%, respectively. • All OPSBs have a great advantage of water recovery from the flue gas, especially OPSB-C. • OPSB-C process is recommended in view of its favorable overall performances

  20. 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.

  1. 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.

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

    International Nuclear Information System (INIS)

    Stoever, R.

    1973-01-01

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

  3. Realization of BP neural network modeling based on NOXof CFB boiler in DCS

    Science.gov (United States)

    Bai, Jianyun; Zhu, Zhujun; Wang, Qi; Ying, Jiang

    2018-02-01

    In the CFB boiler installed with SNCR denitrification system, the mass concentration of NO X is difficult to be predicted by the conventional mathematical model, and the step response mathematical model, obtained by using the step disturbance test of ammonia injection,is inaccurate. this paper presents two kinds of BP neural network model, according to the relationship between the generated mass concentration of NO X and the load, the ratio of air to coal without using the SNCR system, as well as the relationship between the tested mass concentration of NO X and the load, the ratio of air to coal and the amount of ammonia using the SNCR system. then itrealized the on-line prediction of the mass concentration of NO X and the remaining mass concentration of NO X after reductionreaction in DCS system. the practical results show that the average error per hour between generation and the prediction of the amount of NO X mass concentration is within 10 mg/Nm3,the reducing reaction of measured and predicted hourly average error is within 2 mg/Nm3, all in error range, which provides a more accurate model for solvingthe problem on NO X automatic control of SNCR system.

  4. Efficient boiler operations sourcebook

    Energy Technology Data Exchange (ETDEWEB)

    Payne, F.W. (comp.)

    1985-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Prieto, M.M. [Oviedo University, Energy Department, Campus de Viesques, 33204 GIJON. Asturias (Spain)]. E-mail: manuelap@uniovi.es; Suarez, I. [Oviedo University, Energy Department, Campus de Viesques, 33204 GIJON. Asturias (Spain); Fernandez, F.J. [Oviedo University, Energy Department, Campus de Viesques, 33204 GIJON. Asturias (Spain); Sanchez, H. [Central Termica de Soto de Ribera, Ribera de Arriba, Asturias (Spain); Mateos, M. [Central Termica de Soto de Ribera, Ribera de Arriba, Asturias (Spain)

    2007-02-15

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

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

    Science.gov (United States)

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

    2014-05-01

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

  7. Numerical study of furnace process of a 600 MW pulverized coal boiler under low load with SNCR application

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Q.X.; Shi, Y.; Liu, H.; Yang, C.H.; Wu, S.H. [Harbin Institute of Technology, Harbin (China)

    2013-07-01

    Numerical simulation of flow, heat transfer, and combustion process in a 600MW pulverized coal boiler under low load is performed using Computational Fluid Dynamics (CFD) code Fluent. The distributions of temperature and species were obtained and their influences on Selective non-catalytic reduction (SNCR) were analyzed. The results indicate that the furnace temperature changed significantly as the operation load declines. The furnace space with proper temperature for SNCR reaction becomes lower with decreasing of operation load. As the load falls off, the available O{sub 2}concentration for SNCR reactions rises gently and the initial NOx concentration for SNCR reactions debases slightly. These variations can have some influence on the SNCR process. For the upper furnace where the temperature is suitable for SNCR reactions, the CO concentration is close to 0 under different load. Consequently, the SNCR process will not be affected by CO based on the calculation in this work.

  8. Steam boilers : Process models for improved operation and design

    NARCIS (Netherlands)

    Ahnert, F.

    2007-01-01

    Biomass combustion can be an economic way to contribute to the reduction of CO2 emissions, which are a main suspect of the so-called greenhouse effect. In order to promote a widespread utilization of biomass combustion, operational problems like fuel treatment, slagging, fouling and corrosion have

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

    Science.gov (United States)

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

    2018-07-15

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

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-07-01

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

  12. Modeling N2O Reduction and Decomposition in a Circulating Fluidized bed Boiler

    DEFF Research Database (Denmark)

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

    1996-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Polovnikov V.Yu.

    2016-01-01

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

  14. Towards ideal NOx control technology for bio-oils and a gas multi-fuel boiler system using a plasma-chemical hybrid process

    International Nuclear Information System (INIS)

    Fujishima, Hidekatsu; Takekoshi, Kenichi; Kuroki, Tomoyuki; Tanaka, Atsushi; Otsuka, Keiichi; Okubo, Masaaki

    2013-01-01

    Highlights: • A multi-fuel boiler system combined with NO x aftertreatment is developed. • NO x is removed from flue gas by a plasma-chemical hybrid process. • Waste bio-oils are utilized as renewable energy source and for CO 2 reduction. • Ultra low NO x emission less than 2 ppm is achieved. • The boiler system is applicable for industrial use. - Abstract: A super-clean boiler system comprising a multi-fuel boiler and a reactor for plasma-chemical hybrid NO x aftertreatment is developed, and its industrial applications are examined. The purpose of this research is to optimally reduce NO x emission and utilize waste bio-oil as a renewable energy source. First, NO oxidation using indirect plasma at elevated flue gas temperatures is investigated. It is clarified that more than 98% of NO is oxidized when the temperature of the flue gas is less than 130 °C. Three types of waste bio-oils (waste vegetable oil, rice bran oil, and fish oil) are burned in the boiler as fuels with a rotary-type burner for CO 2 reduction considering carbon neutrality. NO x in the flue gases of these bio-oils is effectively reduced by the indirect plasma-chemical hybrid treatment. Ultralow NO x emission less than 2 ppm is achieved for 450 min in the firing of city natural gas fuel. The boiler system can be successfully operated automatically according to unsteady steam demand and using an empirical equation for Na 2 SO 3 supply rate, and can be used in industries as an ideal NO x control technology

  15. Towards a generic, reliable CFD modelling methodology for waste-fired grate boilers

    DEFF Research Database (Denmark)

    Rajh, Boštjan; Yin, Chungen; Samec, Niko

    of the increased CO2 and H2O vapour concentrations on radiative heat transfer in the boiler. The impacts of full buoyancy on turbulence are also investigated. As a validation effort, the temperature profiles at different ports inside the furnace are measured and the experimental values are compared with the CFD...

  16. 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...

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

    International Nuclear Information System (INIS)

    Li Bin; Chen Tingkuan; Yang Dong

    2005-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Prokhorov V.B.,

    2018-04-01

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

  20. Cogeneration Technology Alternatives Study (CTAS). Volume 6: Computer data. Part 1: Coal-fired nocogeneration process boiler, section A

    Science.gov (United States)

    Knightly, W. F.

    1980-01-01

    Various advanced energy conversion systems (ECS) are compared with each other and with current technology systems for their savings in fuel energy, costs, and emissions in individual plants and on a national level. About fifty industrial processes from the largest energy consuming sectors were used as a basis for matching a similar number of energy conversion systems that are considered as candidates which can be made available by the 1985 to 2000 time period. The sectors considered included food, textiles, lumber, paper, chemicals, petroleum, glass, and primary metals. The energy conversion systems included steam and gas turbines, diesels, thermionics, stirling, closed cycle and steam injected gas turbines, and fuel cells. Fuels considered were coal, both coal and petroleum based residual and distillate liquid fuels, and low Btu gas obtained through the on-site gasification of coal. Computer generated reports of the fuel consumption and savings, capital costs, economics and emissions of the cogeneration energy conversion systems (ECS's) heat and power matched to the individual industrial processes are presented for coal fired process boilers. National fuel and emissions savings are also reported for each ECS assuming it alone is implemented.

  1. Cogeneration Technology Alternatives Study (CTAS). Volume 6: Computer data. Part 1: Coal-fired nocogeneration process boiler, section B

    Science.gov (United States)

    Knightly, W. F.

    1980-01-01

    About fifty industrial processes from the largest energy consuming sectors were used as a basis for matching a similar number of energy conversion systems that are considered as candidate which can be made available by the 1985 to 2000 time period. The sectors considered included food, textiles, lumber, paper, chemicals, petroleum, glass, and primary metals. The energy conversion systems included steam and gas turbines, diesels, thermionics, stirling, closed cycle and steam injected gas turbines, and fuel cells. Fuels considered were coal, both coal and petroleum based residual and distillate liquid fuels, and low Btu gas obtained through the on site gasification of coal. Computer generated reports of the fuel consumption and savings, capital costs, economics and emissions of the cogeneration energy conversion systems (ECS's) heat and power matched to the individual industrial processes are presented. National fuel and emissions savings are also reported for each ECS assuming it alone is implemented. Two nocogeneration base cases are included: coal fired and residual fired process boilers.

  2. Numerical investigation of a straw combustion boiler – Part I: Modelling of the thermo-chemical conversion of straw

    Directory of Open Access Journals (Sweden)

    Dernbecher Andrea

    2016-01-01

    Full Text Available In the framework of a European project, a straw combustion boiler in conjunction with an organic Rankine cycle is developed. One objective of the project is the enhancement of the combustion chamber by numerical methods. A comprehensive simulation of the combustion chamber is prepared, which contains the necessary submodels for the thermo-chemical conversion of straw and for the homogeneous gas phase reactions. Part I introduces the modelling approach for the thermal decomposition of the biomass inside the fuel bed, whereas part II deals with the simulation of the gas phase reactions in the freeboard.

  3. 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)

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

    International Nuclear Information System (INIS)

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

    2005-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-12-15

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

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  7. Upgrading of bio-oil to boiler fuel by catalytic hydrotreatment and esterification in an efficient process

    International Nuclear Information System (INIS)

    Zhang, Xinghua; Chen, Lungang; Kong, Wei; Wang, Tiejun; Zhang, Qi; Long, Jinxing; Xu, Ying; Ma, Longlong

    2015-01-01

    Bio-oil can't be directly used as fuel due to its deteriorate properties. Here, an efficient catalytic upgrading process for the bio-oil, including esterification, hydrogenation, hydrodeoxygenation and depolymerization, is proposed with multifunctional catalyst Ni/SiO 2 –ZrO 2 and biomass-derived solvent ethanol. Results showed that esters, alcohols, phenolics, and cyclo-ketones were the main components in the upgraded bio-oil while aldehydes were removed completely via catalytic hydrogenation and acids were removed by catalytic esterification with supercritical ethanol. The pH value of upgraded bio-oil rose drastically from 2.38 to 5.24, and the high heating value increased to 24.4 MJ kg −1 . Comparison characterization on the upgraded and crude bio-oil using FT-IR, GPC (Gel permeation chromatography) and 13 C NMR (Nuclear Magnetic Resonance) demonstrated that lignin-derived oligomers contained in crude bio-oil were further depolymerized over Ni/SiO 2 –ZrO 2 catalyst. The improved properties suggest that the upgraded bio-oil is more suitable to be used as boiler fuel. Furthermore, the loss of carbon is negligible because formation of coke is suppressed during the upgrading process. - Highlights: • Acid can be converted via catalytic esterification in supercritical ethanol. • Aldehydes can be removed completely during the upgrading process. • Lignin-derived oligomers were further depolymerized during the upgrading process. • Formation of coke is effectively inhibited during the upgrading process

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

    Science.gov (United States)

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

    2018-05-01

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

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

    International Nuclear Information System (INIS)

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

    2012-09-01

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

  11. Process to refine flyash captured from pulverized coal fired boilers and auxiliary equipment

    International Nuclear Information System (INIS)

    Borowy, W.J.

    1991-01-01

    This patent describes a separating and refining process for particulate that has been removed from the exhaust gases of an organic fuel combustion process. It includes determining relative sizes of carbon rich and carbon lean particles that are found in the exhaust gases for the combustion process; supplying the particulate matter from the exhaust of the combustion process; providing a means for conveying the particulate matter between the following steps; separating, by size, coarse and fine particles in the exhaust particulate so as to yield carbon rich and carbon lean fractions

  12. 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.

  13. Model Research of Gas Emissions From Lignite and Biomass Co-Combustion in a Large Scale CFB Boiler

    Directory of Open Access Journals (Sweden)

    Krzywański Jarosław

    2014-06-01

    Full Text Available The paper is focused on the idea of a combustion modelling of a large-scale circulating fluidised bed boiler (CFB during coal and biomass co-combustion. Numerical computation results for three solid biomass fuels co-combustion with lignite are presented in the paper. The results of the calculation showed that in previously established kinetics equations for coal combustion, some reactions had to be modified as the combustion conditions changed with the fuel blend composition. Obtained CO2, CO, SO2 and NOx emissions are located in borders of ± 20% in the relationship to the experimental data. Experimental data was obtained for forest biomass, sunflower husk, willow and lignite cocombustion tests carried out on the atmospheric 261 MWe COMPACT CFB boiler operated in PGE Turow Power Station in Poland. The energy fraction of biomass in fuel blend was: 7%wt, 10%wt and 15%wt. The measured emissions of CO, SO2 and NOx (i.e. NO + NO2 were also shown in the paper. For all types of biomass added to the fuel blends the emission of the gaseous pollutants was lower than that for coal combustion.

  14. Analysis of a waste-heat boiler by CFD simulation

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-12-31

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

  15. Analysis of a waste-heat boiler by CFD simulation

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

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

    OpenAIRE

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

    2017-01-01

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

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

    NARCIS (Netherlands)

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

    2013-01-01

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

  19. 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

  20. Boilers, evaporators, and condensers

    International Nuclear Information System (INIS)

    Kakac, S.

    1991-01-01

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

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

    International Nuclear Information System (INIS)

    Qu, Ming; Abdelaziz, Omar; Yin, Hongxi

    2014-01-01

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

  2. Increased combustion stability in modulating biomass boilers for district heating systems

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-09-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-12-15

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

  4. 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

  5. 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

  6. 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)

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-04-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

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

  11. 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.)

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  13. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-01-01

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

  15. Boiler water regime

    Science.gov (United States)

    Khavanov, Pavel; Chulenyov, Anatoly

    2017-10-01

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

  16. Analytical model for erosion behaviour of impacted fly-ash particles ...

    Indian Academy of Sciences (India)

    Mathematical model; erosion rate; boiler components; fly ash ... sion, together with the processes of blocking, fouling and corrosion, shortens the service-life of boiler ..... Jun Y D, Tabakoff W 1994 Numerical simulation of a dilute particulate flow ...

  17. Boiler conversions for biomass

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

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

  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. 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.

  20. 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)

  1. Silva. EDF two-phase 1D annular model of a CFB boiler furnace

    Energy Technology Data Exchange (ETDEWEB)

    Montat, D.; Fauquet, Ph. [Electricite de France (EDF), 78 - Chatou (France). Researckh and Development Div.; Lafanechere, L.; Bursi, J.M. [Electricite de France (EDF) (France). Construction Div.

    1997-01-01

    SILVA computer code is used for the modelling of the thermal-hydraulics and of the combustion of a coal-fired CFBC solid loop. In a first step, only the furnace is considered. The model is based on a 1D annular two phases description of the hydrodynamics. The model is based on particle mass balances and pressure drop calculations. A basic combustion model is incorporated into this model. The coal combustion is divided in two phases, the combustion of volatile matter and the heterogeneous combustion. The model has been developed within LEGO software and can be included into the global model of the solid loop developed by EDF. (author) 26 refs.

  2. CFD analysis of the pulverized coal combustion processes in a 160 MWe tangentially-fired-boiler of a thermal power plant

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Cristiano V. da; Beskow, Arthur B. [Universidade Regional Integrada do Alto Uruguai e das Misses (LABSIM/GEAPI/URI), Erechim, RS (Brazil). Dept. de Engenharia e Ciencia da Computacao. Grupo de Engenharia Aplicada a Processos Industriais], Emails: cristiano@uricer.edu.br, Arthur@uricer.edu.br; Indrusiak, Maria Luiza S. [Universidade do Vale do Rio dos Sinos (UNISINOS), Sao Leopoldo, RS (Brazil). Programa de Engenharia Mecanica], E-mail: sperbindrusiak@via-rs.net

    2010-10-15

    The strategic role of energy and the current concern with greenhouse effects, energetic and exegetic efficiency of fossil fuel combustion greatly enhance the importance of the studies of complex physical and chemical processes occurring inside boilers of thermal power plants. The state of the art in computational fluid dynamics and the availability of commercial codes encourage numeric studies of the combustion processes. In the present work the commercial software CFX Ansys Europe Ltd. was used to study the combustion of coal in a 160 MWe commercial thermal power plant with the objective of simulating the operational conditions and identifying factors of inefficiency. The behavior of the flow of air and pulverized coal through the burners was analyzed, and the three-dimensional flue gas flow through the combustion chamber and heat exchangers was reproduced in the numeric simulation. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1998-12-31

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

  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. Towards a CFD-based mechanistic deposit formation model for straw-fired boilers

    DEFF Research Database (Denmark)

    Kær, Søren Knudsen; Rosendahl, Lasse Aistrup; Baxter, L.L.

    2006-01-01

    is configured entirely through a graphical user interface integrated in the standard FLUENTe interface. The model considers fine and coarse mode ash deposition and sticking mechanisms for the complete deposit growth, as well as an influence on the local boundary conditions for heat transfer due to thermal...... in the reminder of the paper. The growth of deposits on furnace walls and super heater tubes is treated including the impact on heat transfer rates determined by the CFD code. Based on the commercial CFD code FLUENTe, the overall model is fully implemented through the User Defined Functions. The model...

  6. Neural Network Based Model of an Industrial Oil-Fired Boiler System ...

    African Journals Online (AJOL)

    A two-layer feed-forward neural network with Hyperbolic tangent sigmoid ... The neural network model when subjected to test, using the validation input data; ... Proportional Integral Derivative (PID) Controller is used to control the neural ...

  7. Modeling of large-scale oxy-fuel combustion processes

    DEFF Research Database (Denmark)

    Yin, Chungen

    2012-01-01

    Quite some studies have been conducted in order to implement oxy-fuel combustion with flue gas recycle in conventional utility boilers as an effective effort of carbon capture and storage. However, combustion under oxy-fuel conditions is significantly different from conventional air-fuel firing......, among which radiative heat transfer under oxy-fuel conditions is one of the fundamental issues. This paper demonstrates the nongray-gas effects in modeling of large-scale oxy-fuel combustion processes. Oxy-fuel combustion of natural gas in a 609MW utility boiler is numerically studied, in which...... calculation of the oxy-fuel WSGGM remarkably over-predicts the radiative heat transfer to the furnace walls and under-predicts the gas temperature at the furnace exit plane, which also result in a higher incomplete combustion in the gray calculation. Moreover, the gray and non-gray calculations of the same...

  8. 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.

  9. Semantic Business Process Modeling

    OpenAIRE

    Markovic, Ivan

    2010-01-01

    This book presents a process-oriented business modeling framework based on semantic technologies. The framework consists of modeling languages, methods, and tools that allow for semantic modeling of business motivation, business policies and rules, and business processes. Quality of the proposed modeling framework is evaluated based on the modeling content of SAP Solution Composer and several real-world business scenarios.

  10. IAPCS: A COMPUTER MODEL THAT EVALUATES POLLUTION CONTROL SYSTEMS FOR UTILITY BOILERS

    Science.gov (United States)

    The IAPCS model, developed by U.S. EPA`s Air and Energy Engineering Research Laboratory and made available to the public through the National Technical Information Service, can be used by utility companies, architectural and engineering companies, and regulatory agencies at all l...

  11. Dynamic Simulation of an Organic Rankine Cycle—Detailed Model of a Kettle Boiler

    Directory of Open Access Journals (Sweden)

    Roberto Pili

    2017-04-01

    Full Text Available Organic Rankine Cycles (ORCs are nowadays a valuable technology to produce electricity from low and medium temperature heat sources, e.g., in geothermal, biomass and waste heat recovery applications. Dynamic simulations can help improve the flexibility and operation of such plants, and guarantee a better economic performance. In this work, a dynamic model for a multi-pass kettle evaporator of a geothermal ORC power plant has been developed and its dynamics have been validated against measured data. The model combines the finite volume approach on the tube side and a two-volume cavity on the shell side. To validate the dynamic model, a positive and a negative step function in heat source flow rate is applied. The simulation model performed well in both cases. The liquid level appeared the most challenging quantity to simulate. A better agreement in temperature was achieved by increasing the volume flow rate of the geothermal brine by 2% over the entire simulation. Measurement errors, discrepancies in working fluid and thermal brine properties and uncertainties in heat transfer correlations can account for this. In the future, the entire geothermal power plant will be simulated, and suggestions to improve its dynamics and control by means of simulations will be provided.

  12. 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.

  13. CECIL lances Bruce's boilers

    International Nuclear Information System (INIS)

    Malaugh, J.; Monaghan, D.

    1994-01-01

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

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

    International Nuclear Information System (INIS)

    Visser, J.M.

    1995-04-01

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

  15. 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.

  16. Charting the boiler market

    International Nuclear Information System (INIS)

    2003-01-01

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

  17. Dynamic Boiler Performance

    DEFF Research Database (Denmark)

    Sørensen, Kim

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

  18. Assessment of physical workload in boiler operations.

    Science.gov (United States)

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

    2012-01-01

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

  19. Modeling multiphase materials processes

    CERN Document Server

    Iguchi, Manabu

    2010-01-01

    ""Modeling Multiphase Materials Processes: Gas-Liquid Systems"" describes the methodology and application of physical and mathematical modeling to multi-phase flow phenomena in materials processing. The book focuses on systems involving gas-liquid interaction, the most prevalent in current metallurgical processes. The performance characteristics of these processes are largely dependent on transport phenomena. This volume covers the inherent characteristics that complicate the modeling of transport phenomena in such systems, including complex multiphase structure, intense turbulence, opacity of

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  1. Using CFD to investigate heater fouling in a utility boiler

    International Nuclear Information System (INIS)

    Pang, L.; Sun, B.; Salcudean, M.

    2004-01-01

    A simulation investigation into the combustion and heat transfer process in a utility boiler is presented. The work is based on the commercial software Fluent 6.1.18. Flow, chemistry, energy, conservation and radiation models are used to simulate the process inside the furnace. Radiation and convection models are considered in the horizontal heater. The temperature and velocity fields are calculated to unveil the process inside and outside the furnace. The result shows that the fouling in reheater is formed because of the temperature and velocity field in the flue gas passage. A limited test is done to validate the simulation. (author)

  2. Process modeling style

    CERN Document Server

    Long, John

    2014-01-01

    Process Modeling Style focuses on other aspects of process modeling beyond notation that are very important to practitioners. Many people who model processes focus on the specific notation used to create their drawings. While that is important, there are many other aspects to modeling, such as naming, creating identifiers, descriptions, interfaces, patterns, and creating useful process documentation. Experience author John Long focuses on those non-notational aspects of modeling, which practitioners will find invaluable. Gives solid advice for creating roles, work produ

  3. On synthesis and optimization of steam system networks. 1. Sustained boiler efficiency

    CSIR Research Space (South Africa)

    Majozi, T

    2010-08-01

    Full Text Available situations. This paper presents a process integration technique for network synthesis using conceptual and mathematical analysis without compromising boiler efficiency. It was found that the steam flow rate to the HEN could be reduced while maintaining boiler...

  4. Product and Process Modelling

    DEFF Research Database (Denmark)

    Cameron, Ian T.; Gani, Rafiqul

    . These approaches are put into the context of life cycle modelling, where multiscale and multiform modelling is increasingly prevalent in the 21st century. The book commences with a discussion of modern product and process modelling theory and practice followed by a series of case studies drawn from a variety......This book covers the area of product and process modelling via a case study approach. It addresses a wide range of modelling applications with emphasis on modelling methodology and the subsequent in-depth analysis of mathematical models to gain insight via structural aspects of the models...... to biotechnology applications, food, polymer and human health application areas. The book highlights to important nature of modern product and process modelling in the decision making processes across the life cycle. As such it provides an important resource for students, researchers and industrial practitioners....

  5. CFD investigation of flow through internally riffled boiler tubes

    DEFF Research Database (Denmark)

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

    1997-01-01

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

  6. 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.)

  7. 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...

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

    International Nuclear Information System (INIS)

    Fang, Fang; Wei, Le

    2011-01-01

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

  9. Standard Model processes

    CERN Document Server

    Mangano, M.L.; Aguilar-Saavedra, Juan Antonio; Alekhin, S.; Badger, S.; Bauer, C.W.; Becher, T.; Bertone, V.; Bonvini, M.; Boselli, S.; Bothmann, E.; Boughezal, R.; Cacciari, M.; Carloni Calame, C.M.; Caola, F.; Campbell, J.M.; Carrazza, S.; Chiesa, M.; Cieri, L.; Cimaglia, F.; Febres Cordero, F.; Ferrarese, P.; D'Enterria, D.; Ferrera, G.; Garcia i Tormo, X.; Garzelli, M.V.; Germann, E.; Hirschi, V.; Han, T.; Ita, H.; Jäger, B.; Kallweit, S.; Karlberg, A.; Kuttimalai, S.; Krauss, F.; Larkoski, A.J.; Lindert, J.; Luisoni, G.; Maierhöfer, P.; Mattelaer, O.; Martinez, H.; Moch, S.; Montagna, G.; Moretti, M.; Nason, P.; Nicrosini, O.; Oleari, C.; Pagani, D.; Papaefstathiou, A.; Petriello, F.; Piccinini, F.; Pierini, M.; Pierog, T.; Pozzorini, S.; Re, E.; Robens, T.; Rojo, J.; Ruiz, R.; Sakurai, K.; Salam, G.P.; Salfelder, L.; Schönherr, M.; Schulze, M.; Schumann, S.; Selvaggi, M.; Shivaji, A.; Siodmok, A.; Skands, P.; Torrielli, P.; Tramontano, F.; Tsinikos, I.; Tweedie, B.; Vicini, A.; Westhoff, S.; Zaro, M.; Zeppenfeld, D.; CERN. Geneva. ATS Department

    2017-06-22

    This report summarises the properties of Standard Model processes at the 100 TeV pp collider. We document the production rates and typical distributions for a number of benchmark Standard Model processes, and discuss new dynamical phenomena arising at the highest energies available at this collider. We discuss the intrinsic physics interest in the measurement of these Standard Model processes, as well as their role as backgrounds for New Physics searches.

  10. 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.

  11. Control Properties of Bottom Fired Marine Boilers

    DEFF Research Database (Denmark)

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

    2007-01-01

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

  12. EFFICIENCY OF MULTI-MODULE SOLAR COLLECTORS AS A PREFIX TO A BOILER

    Directory of Open Access Journals (Sweden)

    Denysova A.E.

    2014-12-01

    Full Text Available Influencing factors on thermal and economic efficiency of the combined of heat supply installation are established. Constructive circuits of solar heat supply "prefix" interaction with boiler installation are worked out. Mathematical models of heat exchange processes in elements of combined heat supply system with the account solar engineering characteristics are developed. The techniques of analysis of efficiency of multi-modular system of solar collectors with compulsory circulation for water heating boiler allowing calculating of efficiency factor; heat removal factor and heat transfer factor with the account of construction and operation conditions of alternative heat supply system are presented.

  13. 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.

  14. A rule-based industrial boiler selection system

    NARCIS (Netherlands)

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

    2015-01-01

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

  15. 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.

  16. WWTP Process Tank Modelling

    DEFF Research Database (Denmark)

    Laursen, Jesper

    The present thesis considers numerical modeling of activated sludge tanks on municipal wastewater treatment plants. Focus is aimed at integrated modeling where the detailed microbiological model the Activated Sludge Model 3 (ASM3) is combined with a detailed hydrodynamic model based on a numerical...... solution of the Navier-Stokes equations in a multiphase scheme. After a general introduction to the activated sludge tank as a system, the activated sludge tank model is gradually setup in separate stages. The individual sub-processes that are often occurring in activated sludge tanks are initially...... hydrofoil shaped propellers. These two sub-processes deliver the main part of the supplied energy to the activated sludge tank, and for this reason they are important for the mixing conditions in the tank. For other important processes occurring in the activated sludge tank, existing models and measurements...

  17. Influence of boiler load on water tubes burnout

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-07-01

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

  18. A theoretical approach for energy saving in industrial steam boilers

    International Nuclear Information System (INIS)

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

    1993-01-01

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

  19. 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.

  20. 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.

  1. Wood fuelled boiler operating costs

    International Nuclear Information System (INIS)

    Sandars, D.L.

    1995-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Levasseur, Armand

    2014-04-30

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

  3. Model Process Control Language

    Data.gov (United States)

    National Aeronautics and Space Administration — The MPC (Model Process Control) language enables the capture, communication and preservation of a simulation instance, with sufficient detail that it can be...

  4. Optimising boiler performance.

    Science.gov (United States)

    Mayoh, Paul

    2009-01-01

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

  5. Least Square Fast Learning Network for modeling the combustion efficiency of a 300WM coal-fired boiler.

    Science.gov (United States)

    Li, Guoqiang; Niu, Peifeng; Wang, Huaibao; Liu, Yongchao

    2014-03-01

    This paper presents a novel artificial neural network with a very fast learning speed, all of whose weights and biases are determined by the twice Least Square method, so it is called Least Square Fast Learning Network (LSFLN). In addition, there is another difference from conventional neural networks, which is that the output neurons of LSFLN not only receive the information from the hidden layer neurons, but also receive the external information itself directly from the input neurons. In order to test the validity of LSFLN, it is applied to 6 classical regression applications, and also employed to build the functional relation between the combustion efficiency and operating parameters of a 300WM coal-fired boiler. Experimental results show that, compared with other methods, LSFLN with very less hidden neurons could achieve much better regression precision and generalization ability at a much faster learning speed. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Biosphere Process Model Report

    Energy Technology Data Exchange (ETDEWEB)

    J. Schmitt

    2000-05-25

    To evaluate the postclosure performance of a potential monitored geologic repository at Yucca Mountain, a Total System Performance Assessment (TSPA) will be conducted. Nine Process Model Reports (PMRs), including this document, are being developed to summarize the technical basis for each of the process models supporting the TSPA model. These reports cover the following areas: (1) Integrated Site Model; (2) Unsaturated Zone Flow and Transport; (3) Near Field Environment; (4) Engineered Barrier System Degradation, Flow, and Transport; (5) Waste Package Degradation; (6) Waste Form Degradation; (7) Saturated Zone Flow and Transport; (8) Biosphere; and (9) Disruptive Events. Analysis/Model Reports (AMRs) contain the more detailed technical information used to support TSPA and the PMRs. The AMRs consists of data, analyses, models, software, and supporting documentation that will be used to defend the applicability of each process model for evaluating the postclosure performance of the potential Yucca Mountain repository system. This documentation will ensure the traceability of information from its source through its ultimate use in the TSPA-Site Recommendation (SR) and in the National Environmental Policy Act (NEPA) analysis processes. The objective of the Biosphere PMR is to summarize (1) the development of the biosphere model, and (2) the Biosphere Dose Conversion Factors (BDCFs) developed for use in TSPA. The Biosphere PMR does not present or summarize estimates of potential radiation doses to human receptors. Dose calculations are performed as part of TSPA and will be presented in the TSPA documentation. The biosphere model is a component of the process to evaluate postclosure repository performance and regulatory compliance for a potential monitored geologic repository at Yucca Mountain, Nevada. The biosphere model describes those exposure pathways in the biosphere by which radionuclides released from a potential repository could reach a human receptor

  7. Biosphere Process Model Report

    International Nuclear Information System (INIS)

    Schmitt, J.

    2000-01-01

    To evaluate the postclosure performance of a potential monitored geologic repository at Yucca Mountain, a Total System Performance Assessment (TSPA) will be conducted. Nine Process Model Reports (PMRs), including this document, are being developed to summarize the technical basis for each of the process models supporting the TSPA model. These reports cover the following areas: (1) Integrated Site Model; (2) Unsaturated Zone Flow and Transport; (3) Near Field Environment; (4) Engineered Barrier System Degradation, Flow, and Transport; (5) Waste Package Degradation; (6) Waste Form Degradation; (7) Saturated Zone Flow and Transport; (8) Biosphere; and (9) Disruptive Events. Analysis/Model Reports (AMRs) contain the more detailed technical information used to support TSPA and the PMRs. The AMRs consists of data, analyses, models, software, and supporting documentation that will be used to defend the applicability of each process model for evaluating the postclosure performance of the potential Yucca Mountain repository system. This documentation will ensure the traceability of information from its source through its ultimate use in the TSPA-Site Recommendation (SR) and in the National Environmental Policy Act (NEPA) analysis processes. The objective of the Biosphere PMR is to summarize (1) the development of the biosphere model, and (2) the Biosphere Dose Conversion Factors (BDCFs) developed for use in TSPA. The Biosphere PMR does not present or summarize estimates of potential radiation doses to human receptors. Dose calculations are performed as part of TSPA and will be presented in the TSPA documentation. The biosphere model is a component of the process to evaluate postclosure repository performance and regulatory compliance for a potential monitored geologic repository at Yucca Mountain, Nevada. The biosphere model describes those exposure pathways in the biosphere by which radionuclides released from a potential repository could reach a human receptor

  8. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2006-06-30

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

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

    OpenAIRE

    Tingfang Yu; Hongzhen Zhu; Chunhua Peng

    2013-01-01

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

  11. Aerospace Materials Process Modelling

    Science.gov (United States)

    1988-08-01

    Cooling Transformation diagram ( CCT diagram ) When a IT diagram is used in the heat process modelling, we suppose that a sudden cooling (instantaneous...processes. CE, chooses instead to study thermo-mechanical properties referring to a CCT diagram . This is thinked to be more reliable to give a true...k , mm-_____sml l ml A I 1 III 12.4 This determination is however based on the following approximations: i) A CCT diagram is valid only for the

  12. Business Model Process Configurations

    DEFF Research Database (Denmark)

    Taran, Yariv; Nielsen, Christian; Thomsen, Peter

    2015-01-01

    , by developing (inductively) an ontological classification framework, in view of the BM process configurations typology developed. Design/methodology/approach – Given the inconsistencies found in the business model studies (e.g. definitions, configurations, classifications) we adopted the analytical induction...

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

    Directory of Open Access Journals (Sweden)

    J. O. ODIGURE

    2005-06-01

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

  14. Boiler control using on-line determination of moisture content for incoming fuel; Forskning kring pannstyrning med on-line fukthaltsmaetning paa biobraensle

    Energy Technology Data Exchange (ETDEWEB)

    Avelin, Anders; Dahlquist, Erik; Moden, Per Erik

    2008-10-15

    Incoming fuels to the biomass fueled boiler are the main source for uncertainties in the combustion process. Fuel quality has large impact on the combustion and the heat transfer in the boiler. There are several possibilities to control the boiler when the bed temperature varies. Flue gas recirculation is one of the variables used for control of the bed temperature in the boiler. Another parameter to use for controlling the bed temperature is to adjust the humidification of the combustion air. The parameter with the major influence on the bed temperature is the amount of primary air. These three parameters are all used as control variables for control of the bed temperature. One part of the study has been to investigate how much and how fast each parameter influences bed temperature and how the information of the moisture content in the incoming fuel can be used for feed-forward information for controlling bed temperature. At the reception terminal all the incoming deliveries are registered with quality and moisture content. This study has also investigated how to use the information about the moisture content of incoming fuel, based on NIR measurements on the fuel transported in to the boiler, and the fluctuation of the bed temperature. Another question is how to connect this information for the bed control. This part of the study is used to evaluate if the information to the operators about the moisture content from the NIR has affect on the variation of the bed temperature. A process model has been developed of the Bubbling Fluidised Bed boiler (BFB) that is one of the boilers at the power plant in Eskilstuna. The model has been used to analyze the process. Process models have become more common and important in the heat and power industry. Nowadays process models are used for training of the staff in simulators of the real plant and for offline tests of control systems

  15. Fouling control in biomass boilers

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-05-15

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

  16. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-01-15

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

  18. 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.)

  19. Numerical simulation of a biomass fired grate boiler

    DEFF Research Database (Denmark)

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

    2006-01-01

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

  20. 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)

  1. Business process model repositories : efficient process retrieval

    NARCIS (Netherlands)

    Yan, Z.

    2012-01-01

    As organizations increasingly work in process-oriented manner, the number of business process models that they develop and have to maintain increases. As a consequence, it has become common for organizations to have collections of hundreds or even thousands of business process models. When a

  2. Demand-based maintenance and operators support based on process models; Behovsstyrt underhaall och operatoersstoed baserat paa process modeller

    Energy Technology Data Exchange (ETDEWEB)

    Dahlquist, Erik; Widarsson, Bjoern; Tomas-Aparicio, Elena

    2012-02-15

    There is a strong demand for systems that can give early warnings on upcoming problems in process performance or sensor measurements. In this project we have developed and implemented such a system on-line. The goal with the system is to give warnings about both faults needing urgent actions, as well giving advice on roughly when service may be needed for specific functions. The use of process simulation models on-line can offer a significant tool for operators and process engineers to analyse the performance of the process and make the most correct and fastest decision when problems arise. In this project physical simulation models are used in combination with decision support tools. By using a physical model it is possible to compare the measured data to the data obtained from the simulation and give these deviations as input to a decision support tool with Bayesian Networks (BN) that will result in information about the probability for wrong measurement in the instruments, process problems and maintenance needs. The application has been implemented in a CFB boiler at Maelarenergi AB. After tuning the model the system has been used online during September - October 2010 and May - October 2011, showing that the system is working on-line with respect to running the simulation model but with batch runs with respect to the BN. Examples have been made for several variables where trends of the deviation between simulation results and measured data have been used as input to a BN, where the probability for different faults has been calculated. Combustion up in the separator/cyclones has been detected several times, problems with fuel feed on both sides of the boiler as well. A moisture sensor not functioning as it should and suspected malfunctioning temperature meters as well. Deeper investigations of the true cause of problems have been used as input to tune the BN

  3. Modelación energética y operacional del sistema de agua de alimentar caldera de una central termoeléctrica; Modeling energetic and operational of the boiler feed water system of a power plant

    Directory of Open Access Journals (Sweden)

    Ernesto Miguel Solís Alemán

    2015-09-01

    Full Text Available Se propone un modelo combinado basado en la implementación paralela de dos aproximadores funcionales, utilizando una red neuronal del tipo (MLP y una regresión estadística, para la obtención de las características energéticas y de operación actual del Sistema de Agua de Alimentar Caldera (SAAC en una Central Termoeléctrica (CTE, en la cual se regula el flujo de agua a la caldera por variación de velocidad. La respuesta del modelo combinado se obtiene a partir de la suma ponderada de cada aproximador funcional. Dicho modelo es utilizado para relacionar el consumo de corriente y la posición del variador de velocidad, en función de la presión de descarga y el flujo entregado por cada bomba del SAAC. Para el ajuste de los modelos se utilizan mediciones almacenadas en el archivo histórico del sistema SCADA, donde se aplica un método de procesamiento de datos para eliminar ruidos que pueden afectar el ajuste de los modelos propuestos.Is proposed a combined model based on the parallel implementation of two functional approximators, using a neural network of the type (MLP and a statistical regression to obtain the actual energetic and operation characteristics of the Boiler Feed Water System (BFWS in a Power Plant, in which the water flow to the boiler is controlled by variation speed. The response of the combined model is obtained from the weighted sum of each functional approximator. This model is used to relate the current consumption and the position of the speed variator, in function of the discharge pressure and flow delivered by each pump of the BFWS. For the fit of the models is used save measurements of the historical file of the SCADA system, where is applied a data processing method to eliminating noise that can affect the fit of the models proposed.

  4. 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...

  5. Coal reburning technology for cyclone boilers

    International Nuclear Information System (INIS)

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

    1990-01-01

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

  6. 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

  7. Process model repositories and PNML

    NARCIS (Netherlands)

    Hee, van K.M.; Post, R.D.J.; Somers, L.J.A.M.; Werf, van der J.M.E.M.; Kindler, E.

    2004-01-01

    Bringing system and process models together in repositories facilitates the interchange of model information between modelling tools, and allows the combination and interlinking of complementary models. Petriweb is a web application for managing such repositories. It supports hierarchical process

  8. An optimising controller for Hinkley Point B AGR boilers

    International Nuclear Information System (INIS)

    Wells, C.

    1986-01-01

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

  9. Economical analyses of construction of a biomass boiler house

    International Nuclear Information System (INIS)

    Normak, A.

    2002-01-01

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

  10. Life cycle analysis of small scale pellet boilers characterized by high efficiency and low emissions

    International Nuclear Information System (INIS)

    Monteleone, B.; Chiesa, M.; Marzuoli, R.; Verma, V.K.; Schwarz, M.; Carlon, E.; Schmidl, C.; Ballarin Denti, A.

    2015-01-01

    Highlights: • LCA was performed on innovative small scale pellet boilers. • Pellet boilers impacts were compared to oil and natural gas boilers impacts. • Both literature and experimental data were used for life cycle analysis. • The environmental impact due to all life cycle phases was envisaged. • Sensitivity tests evidenced realistic ways for pellet boilers impact reduction. - Abstract: This study focuses on the environmental impact assessment through Life Cycle Analysis (LCA) of two innovative 10 kW pellet boilers. In particular, the second boiler represents a technological evolution of the first one developed to improve its performance in terms of efficiency and environmental impact. For both boilers, emission factors measured during laboratory tests (full load tests and specific load cycle tests representative of real life boiler operation) have been used as input data in the life cycle analysis. The SimaPro software (v.8.0.4.30) was used for the LCA and the ReCiPe Midpoint method (European version H) was chosen to assess the environmental impact of all boilers (according to LCA ISO standards). In addition, the ReCiPe Endpoint method was used to compare the final results of all 5 boilers with literature data. The pelletisation process represented the most relevant share of the overall environmental impact followed by the operational phase, the manufacturing phase and the disposal phase. A sensitivity analysis performed on the most efficient pellet boiler evidenced the variation of the boiler’s environmental impact as a function of PM10 and NO X emission factors with respect to emission factors monitored during boiler full load operation. Moreover, the reduction of the boiler’s weight and the adoption of new electronic components led to a consistent reduction (−18%) of its environmental impact with respect to the previous technology. A second LCA has been carried on for a 15 kW oil boiler, a 15 kW natural gas boiler and a 15 kW pellet boiler

  11. 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

  12. Numerical investigation of ash deposition in straw-fired boilers

    DEFF Research Database (Denmark)

    Kær, Søren Knudsen

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

  13. Modeling styles in business process modeling

    NARCIS (Netherlands)

    Pinggera, J.; Soffer, P.; Zugal, S.; Weber, B.; Weidlich, M.; Fahland, D.; Reijers, H.A.; Mendling, J.; Bider, I.; Halpin, T.; Krogstie, J.; Nurcan, S.; Proper, E.; Schmidt, R.; Soffer, P.; Wrycza, S.

    2012-01-01

    Research on quality issues of business process models has recently begun to explore the process of creating process models. As a consequence, the question arises whether different ways of creating process models exist. In this vein, we observed 115 students engaged in the act of modeling, recording

  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. A Refrigerated Web Camera for Photogrammetric Video Measurement inside Biomass Boilers and Combustion Analysis

    Directory of Open Access Journals (Sweden)

    Enrique Granada

    2011-01-01

    Full Text Available This paper describes a prototype instrumentation system for photogrammetric measuring of bed and ash layers, as well as for flying particle detection and pursuit using a single device (CCD web camera. The system was designed to obtain images of the combustion process in the interior of a domestic boiler. It includes a cooling system, needed because of the high temperatures in the combustion chamber of the boiler. The cooling system was designed using CFD simulations to ensure effectiveness. This method allows more complete and real-time monitoring of the combustion process taking place inside a boiler. The information gained from this system may facilitate the optimisation of boiler processes.

  16. A refrigerated web camera for photogrammetric video measurement inside biomass boilers and combustion analysis.

    Science.gov (United States)

    Porteiro, Jacobo; Riveiro, Belén; Granada, Enrique; Armesto, Julia; Eguía, Pablo; Collazo, Joaquín

    2011-01-01

    This paper describes a prototype instrumentation system for photogrammetric measuring of bed and ash layers, as well as for flying particle detection and pursuit using a single device (CCD) web camera. The system was designed to obtain images of the combustion process in the interior of a domestic boiler. It includes a cooling system, needed because of the high temperatures in the combustion chamber of the boiler. The cooling system was designed using CFD simulations to ensure effectiveness. This method allows more complete and real-time monitoring of the combustion process taking place inside a boiler. The information gained from this system may facilitate the optimisation of boiler processes.

  17. 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.

  18. 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.

  19. A comparison of fuzzy logic and cluster renewal approaches for heat transfer modeling in a 1296 t/h CFB boiler with low level of flue gas recirculation

    Directory of Open Access Journals (Sweden)

    Błaszczuk Artur

    2017-03-01

    Full Text Available The interrelation between fuzzy logic and cluster renewal approaches for heat transfer modeling in a circulating fluidized bed (CFB has been established based on a local furnace data. The furnace data have been measured in a 1296 t/h CFB boiler with low level of flue gas recirculation. In the present study, the bed temperature and suspension density were treated as experimental variables along the furnace height. The measured bed temperature and suspension density were varied in the range of 1131-1156 K and 1.93-6.32 kg/m3, respectively. Using the heat transfer coefficient for commercial CFB combustor, two empirical heat transfer correlation were developed in terms of important operating parameters including bed temperature and also suspension density. The fuzzy logic results were found to be in good agreement with the corresponding experimental heat transfer data obtained based on cluster renewal approach. The predicted bed-to-wall heat transfer coefficient covered a range of 109-241 W/(m2K and 111-240 W/(m2K, for fuzzy logic and cluster renewal approach respectively. The divergence in calculated heat flux recovery along the furnace height between fuzzy logic and cluster renewal approach did not exceeded ±2%.

  20. Boiler for combustion fuel in a fluidized bed

    Directory of Open Access Journals (Sweden)

    Laković Mirjana S.

    2015-01-01

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

  1. 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

  2. 49 CFR 230.47 - Boiler number.

    Science.gov (United States)

    2010-10-01

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

  3. 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...

  4. 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...

  5. 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...

  6. Optimization of a Centrifugal Boiler Circulating Pump's Casing Based on CFD and FEM Analyses

    OpenAIRE

    Zhigang Zuo; Shuhong Liu; Yizhang Fan; Yulin Wu

    2014-01-01

    It is important to evaluate the economic efficiency of boiler circulating pumps in manufacturing process from the manufacturers' point of view. The possibility of optimizing the pump casing with respect to structural pressure integrity and hydraulic performance was discussed. CFD analyses of pump models with different pump casing sizes were firstly carried out for the hydraulic performance evaluation. The effects of the working temperature and the sealing ring on the hydraulic efficiency were...

  7. Three-dimensional computer simulation for combustion and NO{sub x} emission in a grate fired boiler at Baeckhamars, Sweden. Technical report[(Baeckhammars Bruk)

    Energy Technology Data Exchange (ETDEWEB)

    Dong Wei [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Metallurgy

    2000-05-01

    This report describes the fundament of mathematical modeling for the grate fired boilers in Part A, and presents the results from the numerical simulations for the flow pattern, combustion and NO{sub x} emission in the Baeckhammars grate fired boiler in Part B. The simulated boiler is equipped with a new secondary air supply system called Ecotube. The objective of this project is to develop and experimentally verify tools for computer simulations of solid biomass fuel combustion processes in a grate fired boiler. The work focuses on the numerical simulation using CFD technique and development of a NO{sub x} post processor. The unstructured mesh technique also has been used to discretize the boiler. An unstructured grid with total 284399 tetrahedral cells describes the three dimensional geometry and is used for flow field and combustion simulations. In order to simulate the combustion process in the boiler, a simplified grate bed model -- black-box bed model is used, which is based on the balance analysis of mass and energy on the grate bed and needless to consider any detailed and very difficult dynamic processes which have not been valuable by mathematical modeling on the grate bed yet. Therefore, it is quite convenient for industrial applications. In this work, both the cyanide route and the ammonia route for modeling the fuel containing nitrogen NO{sub x} are developed, and the former has been used to predict the NO generation in Baeckhammars bark boiler. Two 3D cases corresponding to 15 MW and 11 MW output thermal power respectively are simulated in detail. Results show that a new air supply system called Ecotube gives a considerably more uniform velocity, temperature and concentration distribution from the secondary air tubes to the upper part of the furnace. The upper furnace works almost as a 'plug flow reactor' which gives sufficient residence time for CO conversion and low NO{sub x} emission. The calculations of flow and mixing patterns in the

  8. 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...

  9. Influence of process parameters on coal combustion performance. Review, experiments and engineering modeling

    Energy Technology Data Exchange (ETDEWEB)

    Lans, R.P. van der

    1997-04-01

    The objective of this study is to improve the understanding of nitrogen oxide formation and carbon burnout during the combustion of pulverized coal, and to contribute to addressing the potential of chemical engineering models for the prediction of furnace temperatures, NO emissions and the amount of carbon in ash. To this purpose, the effect of coal quality on NO and burnout has been investigated experimentally, a radiation heat balance has been developed based on a simple chemical engineering methodology, and a mixing study has been conducted in order to describe the near burner macro mixing in terms of a reactor configuration. The influence of coal type and process conditions on NO formation and carbon burnout has been investigated experimentally in a 400 MW{sub e} corner fired boiler with over fire air, a 350 MW{sub e} opposed fired boiler, and in a 160 kW{sub t} pilot scale test rig. Three different coals were fired in each of the furnaces as part of the activities in group 3 of the European Union JOULE 2 Extension project `Atmospheric Pressure Combustion of Pulverized Coal and Coal Based Blends for Power Generation`. On the pilot scale test both single stage and air staged tests were performed. A simple, one-dimensional combustion and radiation heat transfer model has been developed for the furnace of full scale boilers. The model has been applied to the two boilers mentioned above, and is validated against measured temperatures and carbon in ash concentrations. A mixing study has been performed in order to initiate an investigation of the potential of chemical engineering models to predict NO from pulverized fuel burners. (EG) 11 refs.

  10. 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.

  11. Electrostatic precipitator performance and trace element emissions from two Kraft recovery boilers.

    Science.gov (United States)

    Lind, Terttaliisa; Hokkinen, Jouni; Jokiniemi, Jorma K; Hillamo, Risto; Makkonen, Ulla; Raukola, Antti; Rintanen, Jaakko; Saviharju, Kari

    2006-01-15

    Fine particle emissions from combustion sources have gained attention recently due to their adverse effects on human health. The emission depends on the combustion process, fuel, and particulate removal technology. Particle concentrations at Kraft recovery boiler exits are very high, and the boilers are typically equipped with electrostatic precipitators (ESP). However, little data are available on the ESP performance in recovery boilers. Particle concentrations and size distributions were determined at two modern, operating recovery boilers. In addition, we determined the fractional collection efficiency of the ESPs by simultaneous measurements at the ESP inlet and outlet and the particulate emissions of trace metals. The particle mass concentration atthe ESP inlet was 11-24 g/Nm3 at the two boilers. Particle emissions were 30-40 mg/ Nm3 at boiler A and 12-15 mg/Nm3 at boiler B. The particle size distributions had a major particle mode at around 1 microm. These fume particles contained most of the particle mass. The main components in the particles were sodium and sulfate with minor amounts of chloride, potassium, and presumably some carbonate. The ESP collection efficiency was 99.6-99.8% at boiler A and 99.9% at boiler B. The particle penetration through the ESP was below 0.6% in the entire fume particle size range of 0.3-3 microm. Trace element emissions from both boilers were well below the limit values set by EU directive for waste incineration.

  12. Fracture analysis of tube boiler for physical explosion accident.

    Science.gov (United States)

    Kim, Eui Soo

    2017-09-01

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

  13. Generating process model collections

    NARCIS (Netherlands)

    Yan, Z.; Dijkman, R.M.; Grefen, P.W.P.J.

    2017-01-01

    Business process management plays an important role in the management of organizations. More and more organizations describe their operations as business processes. It is common for organizations to have collections of thousands of business processes, but for reasons of confidentiality these

  14. 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.

  15. Computations of NOx emissions of domestic boilers

    Energy Technology Data Exchange (ETDEWEB)

    Thevenin, D. [Ecole Centrale de Paris, 92 - Chatenay-Malabry (France). EM2C Lab.; Gicquel, O.; Darabiha, N.

    2001-07-01

    Due to severe regulations concerning pollutant emissions, practical devices using combustion to release energy must be designed from the start using accurate, predictive numerical tools. A partially premixed methane/air flame in a two-dimensional configuration is investigated in this work. This configuration is close to those used in real domestic gas boilers. The flame structure and flow pattern are calculated using complex chemistry and detailed transport models. A post-processing method is then used to predict NO emission. Computations are performed for two configurations. The two cases have the same primary and secondary mass flow-rates and equivalence ratio. The only difference between them is the introduction of an insert inside the primary injector. Both results have been compared to measurements. Calculations are found to be in good agreement with the flame shapes observed experimentally. The classical burner shows a Bunsen-type flame while the one with an insert has a totally different shape (butterfly-type flame). NO emission levels are also well predicted in both configurations. The butterfly flame induces a reduction in NO emission. This reduction seems to be due to the increased mixing between the burnt gases and the secondary air jet, which homogenizes the temperature distribution and reduces the maximum temperature. (orig.)

  16. What makes process models understandable?

    NARCIS (Netherlands)

    Mendling, J.; Reijers, H.A.; Cardoso, J.; Alonso, G.; Dadam, P.; Rosemann, M.

    2007-01-01

    Despite that formal and informal quality aspects are of significant importance to business process modeling, there is only little empirical work reported on process model quality and its impact factors. In this paper we investigate understandability as a proxy for quality of process models and focus

  17. 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.

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

    DEFF Research Database (Denmark)

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

    2010-01-01

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

  19. 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

  20. The processing of bed ashes of fluidized bed boilers to an applicable ingredient for building materials. Het bewerken van bedassen van wervelbedketels tot een geschikte grondstof voor toepassing in bouwprodukten

    Energy Technology Data Exchange (ETDEWEB)

    Dekker, W

    1988-01-01

    A study- and test program has been carried out to determine in what way bed ashes of fluidized bed boilers can be processed to applicate the products in building products. The program consisted of selecting applicable ashes; physical-chemical research; slack lime, present in the ashes; grinding and wind-sifting of the ashes; evaluation of the quality of the acquired samples for application in calcium-silicate brick and in mortar; the making of flow-sheets of the processing in the potential demonstration projects. The used sample was a bed ash with active CaO content of 21%. Conclusions were stated and recommendations were made. 6 figs., 6 refs., 9 tabs., 2 app.

  1. Advanced air/flue gas staging based on CFD modelling for enhanced combustion and burnout in a waste-wood fired boiler

    DEFF Research Database (Denmark)

    Rajh, Boštjan; Yin, Chungen; Samec, Niko

    2017-01-01

    The paper presents the impacts of the jet momentum, position and orientation of air and Recycled Flue Gas (RFG) streams on the performance of a grate-fired boiler burning waste wood via a comprehensive CFD-based parametric study. It is found that the air and RFG jets can be optimized to enhance m...

  2. Influence of burner form and pellet type on domestic pellet boiler performance

    Science.gov (United States)

    Rastvorov, D. V.; Osintsev, K. V.; Toropov, E. V.

    2017-10-01

    The study presents combustion and emission results obtained using two serial pellet boilers of the same heating capacity 40 kW. These boilers have been designed by producers for domestic conditions of exploitation. The principal difference between boilers was the type of the burner. The study concerns the efficiency and ecological performance difference between burners of circular and rectangular forms. The features of the combustion process in both types of burners were studied when boiler operated with different sorts of pellets. The results suggest that the burner of circular form excels the rectangular form burner. However, there is some difference of NOx emission between circular and rectangular burners.

  3. Boiler using combustible fluid

    Science.gov (United States)

    Baumgartner, H.; Meier, J.G.

    1974-07-03

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

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

    Science.gov (United States)

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

    2018-05-01

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

  5. Factors controlling alkalisalt deposition in recovery boiler- release mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    McKeough, P.; Kylloenen, H.; Kurkela, M. [VTT Energy, Espoo (Finland). Process Technology Group

    1996-12-01

    As part of a cooperative effort to develop a model to describe the behaviour of inorganic compounds in kraft recovery boilers, an experimental investigation of the release of sulphur during black liquor pyrolysis has been undertaken. Previous to these studies, the mechanisms of sulphur release and the reasons for the observed effects of process conditions on sulphur release were very poorly understood. On the basis of the experimental results, the main reactions leading to sulphur release have been elucidated with a fair degree of certainty. Logical explanations for the variations of sulphur release with temperature and with liquor solids content have been proposed. The influence of pressure has been investigated in order to gain insights into the effects of mass transfer on the sulphur-release rate. In the near future, the research will be aimed at generating the kinetic data necessary for modelling the release of sulphur in the recovery furnace. (author)

  6. Advanced CFD modeling techniques for improved predictions of SNCR performance for NO{sub x} control in utility boilers

    Energy Technology Data Exchange (ETDEWEB)

    Cremer, M.A.; Montgomery, C.J.; Swensen, D.A.; Wang, D.H.; Heap, M.P.

    2000-07-01

    Conditions for the selective noncatalytic reduction (SNCR) of NO to N{sub 2} by ammonia in the presence of excess oxygen were first identified by Lyon nearly twenty-five years ago. Since that time, researchers have investigated the effectiveness of other reagents, such as urea and cyanuric acid and effects of process parameters such as temperature, residence time, normalized stoichiometric ratio (NSR), equivalence ratio, initial NOx level, and various additives on SNCR performance. In practical combustion systems, NOx reduction efficiencies are primarily dependent on three factors: (1) mixing, (2) temperature, and (3) residence time. Efficiencies increase when all three act in concert so that the reagent is fully mixed with the flue gas at optimum temperatures over a sufficient time. In practical combustion system, severe design constraints are placed on the reagent injection system that must disperse the reagent throughout the entire combustion product stream while the gases are within the appropriate temperature window. Thus, the design of an SNCR injection system requires an analysis capability that takes into account the nonlinear coupling between these physical processes. In particular, it is critical to (1) couple robust finite-rate SNCR chemistry to the flow field computations, and (2) reduce the time associated with the analysis so that the CFD-based analysis remains feasible for design purposes. This paper addresses these 2 issues.

  7. Neuroscientific Model of Motivational Process

    OpenAIRE

    Kim, Sung-il

    2013-01-01

    Considering the neuroscientific findings on reward, learning, value, decision-making, and cognitive control, motivation can be parsed into three sub processes, a process of generating motivation, a process of maintaining motivation, and a process of regulating motivation. I propose a tentative neuroscientific model of motivational processes which consists of three distinct but continuous sub processes, namely reward-driven approach, value-based decision-making, and goal-directed control. Rewa...

  8. Model-free adaptive control of advanced power plants

    Science.gov (United States)

    Cheng, George Shu-Xing; Mulkey, Steven L.; Wang, Qiang

    2015-08-18

    A novel 3-Input-3-Output (3.times.3) Model-Free Adaptive (MFA) controller with a set of artificial neural networks as part of the controller is introduced. A 3.times.3 MFA control system using the inventive 3.times.3 MFA controller is described to control key process variables including Power, Steam Throttle Pressure, and Steam Temperature of boiler-turbine-generator (BTG) units in conventional and advanced power plants. Those advanced power plants may comprise Once-Through Supercritical (OTSC) Boilers, Circulating Fluidized-Bed (CFB) Boilers, and Once-Through Supercritical Circulating Fluidized-Bed (OTSC CFB) Boilers.

  9. 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.

  10. Technical-and-Economic Efficiency of Draft Enriched with Oxygen in Small-Capacity Heating Boilers

    Directory of Open Access Journals (Sweden)

    P. Ratnikov

    2013-01-01

    Full Text Available Data on complex experimental and theoretical investigations pertaining to efficiency of oxygen-enriched draft in the small-capacity heating boilers as exemplified by the plant HEIZA (HW-S-10/K have been presented in the paper. The paper provides a calculation model of heating processes in heat generator burner (as exemplified by HEIZA plant. Simulation of heating processes in the operational zone has been executed in paper. The experimental data have proved model adequacy. The calculation scheme of the plant will be used in future for determination of power and ecological efficiency of draft enrichment with oxygen.

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

    Science.gov (United States)

    Yang, Dong

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

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

    International Nuclear Information System (INIS)

    Keiser, J.R.

    2001-01-01

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

  13. Computational modeling and analysis of heavy water losses in boiler blow down with different positions of BBW-V100 at KANUPP

    International Nuclear Information System (INIS)

    Maqbool, M. U.

    2012-01-01

    The term blowdown is referred to the boilers and steam generators. Blowing down water from the steam generators maintains the chemistry of the feedwater and helps prevent scaling or sludge formation. In a nuclear power plant, the primary loop contains some activity in the form of tritium content. In boilers, primary and secondary systems interface and due to the pressure difference there is always a chance of mixing of primary and secondary fluids in event of tube leak. This primary fluid i.e., heavy water in our case can be lost through the blowdown lines after mixing with the feedwater. This thesis is a computational work for the determination of heavy water losses through the blowdown lines. (author)

  14. Modeling of column apparatus processes

    CERN Document Server

    Boyadjiev, Christo; Boyadjiev, Boyan; Popova-Krumova, Petya

    2016-01-01

    This book presents a new approach for the modeling of chemical and interphase mass transfer processes in industrial column apparatuses, using convection-diffusion and average-concentration models. The convection-diffusion type models are used for a qualitative analysis of the processes and to assess the main, small and slight physical effects, and then reject the slight effects. As a result, the process mechanism can be identified. It also introduces average concentration models for quantitative analysis, which use the average values of the velocity and concentration over the cross-sectional area of the column. The new models are used to analyze different processes (simple and complex chemical reactions, absorption, adsorption and catalytic reactions), and make it possible to model the processes of gas purification with sulfur dioxide, which form the basis of several patents.

  15. UML in business process modeling

    Directory of Open Access Journals (Sweden)

    Bartosz Marcinkowski

    2013-03-01

    Full Text Available Selection and proper application of business process modeling methods and techniques have a significant impact on organizational improvement capabilities as well as proper understanding of functionality of information systems that shall support activity of the organization. A number of business process modeling notations were popularized in practice in recent decades. Most significant of the notations include Business Process Modeling Notation (OMG BPMN and several Unified Modeling Language (OMG UML extensions. In this paper, the assessment whether one of the most flexible and strictly standardized contemporary business process modeling notations, i.e. Rational UML Profile for Business Modeling, enable business analysts to prepare business models that are all-embracing and understandable by all the stakeholders. After the introduction, methodology of research is discussed. Section 2 presents selected case study results. The paper is concluded with a summary.

  16. 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.

  17. Cracking and corrosion recovery boiler

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-12-31

    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.

  18. Business Process Modeling: Perceived Benefits

    Science.gov (United States)

    Indulska, Marta; Green, Peter; Recker, Jan; Rosemann, Michael

    The process-centered design of organizations and information systems is globally seen as an appropriate response to the increased economic pressure on organizations. At the methodological core of process-centered management is process modeling. However, business process modeling in large initiatives can be a time-consuming and costly exercise, making it potentially difficult to convince executive management of its benefits. To date, and despite substantial interest and research in the area of process modeling, the understanding of the actual benefits of process modeling in academia and practice is limited. To address this gap, this paper explores the perception of benefits derived from process modeling initiatives, as reported through a global Delphi study. The study incorporates the views of three groups of stakeholders - academics, practitioners and vendors. Our findings lead to the first identification and ranking of 19 unique benefits associated with process modeling. The study in particular found that process modeling benefits vary significantly between practitioners and academics. We argue that the variations may point to a disconnect between research projects and practical demands.

  19. Optimizing the Integrated Design of Boilers - Simulation

    DEFF Research Database (Denmark)

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

    2004-01-01

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

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

    OpenAIRE

    Chayalakshmi C.L

    2018-01-01

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

  1. Conceptual models of information processing

    Science.gov (United States)

    Stewart, L. J.

    1983-01-01

    The conceptual information processing issues are examined. Human information processing is defined as an active cognitive process that is analogous to a system. It is the flow and transformation of information within a human. The human is viewed as an active information seeker who is constantly receiving, processing, and acting upon the surrounding environmental stimuli. Human information processing models are conceptual representations of cognitive behaviors. Models of information processing are useful in representing the different theoretical positions and in attempting to define the limits and capabilities of human memory. It is concluded that an understanding of conceptual human information processing models and their applications to systems design leads to a better human factors approach.

  2. Business process modeling in healthcare.

    Science.gov (United States)

    Ruiz, Francisco; Garcia, Felix; Calahorra, Luis; Llorente, César; Gonçalves, Luis; Daniel, Christel; Blobel, Bernd

    2012-01-01

    The importance of the process point of view is not restricted to a specific enterprise sector. In the field of health, as a result of the nature of the service offered, health institutions' processes are also the basis for decision making which is focused on achieving their objective of providing quality medical assistance. In this chapter the application of business process modelling - using the Business Process Modelling Notation (BPMN) standard is described. Main challenges of business process modelling in healthcare are the definition of healthcare processes, the multi-disciplinary nature of healthcare, the flexibility and variability of the activities involved in health care processes, the need of interoperability between multiple information systems, and the continuous updating of scientific knowledge in healthcare.

  3. Modeling nuclear processes by Simulink

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Nahrul Khair Alang Md, E-mail: nahrul@iium.edu.my [Faculty of Engineering, International Islamic University Malaysia, Jalan Gombak, Selangor (Malaysia)

    2015-04-29

    Modelling and simulation are essential parts in the study of dynamic systems behaviours. In nuclear engineering, modelling and simulation are important to assess the expected results of an experiment before the actual experiment is conducted or in the design of nuclear facilities. In education, modelling can give insight into the dynamic of systems and processes. Most nuclear processes can be described by ordinary or partial differential equations. Efforts expended to solve the equations using analytical or numerical solutions consume time and distract attention from the objectives of modelling itself. This paper presents the use of Simulink, a MATLAB toolbox software that is widely used in control engineering, as a modelling platform for the study of nuclear processes including nuclear reactor behaviours. Starting from the describing equations, Simulink models for heat transfer, radionuclide decay process, delayed neutrons effect, reactor point kinetic equations with delayed neutron groups, and the effect of temperature feedback are used as examples.

  4. Modeling nuclear processes by Simulink

    International Nuclear Information System (INIS)

    Rashid, Nahrul Khair Alang Md

    2015-01-01

    Modelling and simulation are essential parts in the study of dynamic systems behaviours. In nuclear engineering, modelling and simulation are important to assess the expected results of an experiment before the actual experiment is conducted or in the design of nuclear facilities. In education, modelling can give insight into the dynamic of systems and processes. Most nuclear processes can be described by ordinary or partial differential equations. Efforts expended to solve the equations using analytical or numerical solutions consume time and distract attention from the objectives of modelling itself. This paper presents the use of Simulink, a MATLAB toolbox software that is widely used in control engineering, as a modelling platform for the study of nuclear processes including nuclear reactor behaviours. Starting from the describing equations, Simulink models for heat transfer, radionuclide decay process, delayed neutrons effect, reactor point kinetic equations with delayed neutron groups, and the effect of temperature feedback are used as examples

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  6. modeling grinding modeling grinding processes as micro processes

    African Journals Online (AJOL)

    eobe

    industrial precision grinding processes are cylindrical, center less and ... Several model shave been proposed and used to study grinding ..... grinding force for the two cases were 9.07237N/mm ..... International Journal of Machine Tools &.

  7. Multiloop control of a drum boiler

    Directory of Open Access Journals (Sweden)

    Alena Kozáková

    2014-05-01

    Full Text Available The Equivalent Subsystems Method (ESM (Kozáková et al., 2011 is methodology of decentralized controller design in the frequency domain which allows designing local controllers using any SISO frequency domain method. The paper deals with the digital ESM version where digital local PID controllers guaranteeing required performance for the full system are designed for individual equivalent subsystems using the practice-oriented Sine-wave method (Bucz et al., 2012. The proposed decentralized controller design procedure was verified on the nonlinear benchmark drum boiler simulation model (Morilla, 2012.

  8. Introduction of low-temperature swirl technology of burning as a way of increase in ecological of low power boilers

    Science.gov (United States)

    Trinchenko, A. A.; Paramonov, A. P.

    2017-10-01

    Work is devoted to the solution of problems of energy efficiency increase in low power boilers at combustion of solid fuel. The technological method of nitrogen oxides decomposition on a surface of carbon particles with education environmentally friendly carbonic acid and molecular nitrogen is considered during the work of a low-temperature swirl fire chamber. Based on the analysis of physical and chemical processes of a fuel chemically connected energy transition into thermal, using the diffusive and kinetic theory of burning modern approaches the technique, mathematical model and the settlement program for assessment of plant ecological indicators when using a new method are developed. Alternative calculations of furnace process are carried out, quantitative assessment of nitrogen oxides emissions level of the reconstructed boiler is executed. The results of modeling and experimental data have approved that the organization of swirl burning increases overall performance of a fire chamber and considerably reduces emissions of nitrogen oxides.

  9. Adsorption thermal energy storage for cogeneration in industrial batch processes: Experiment, dynamic modeling and system analysis

    International Nuclear Information System (INIS)

    Schreiber, Heike; Graf, Stefan; Lanzerath, Franz; Bardow, André

    2015-01-01

    Adsorption thermal energy storage is investigated for heat supply with cogeneration in industrial batch processes. The feasibility of adsorption thermal energy storage is demonstrated with a lab-scale prototype. Based on these experiments, a dynamic model is developed and successfully calibrated to measurement data. Thereby, a reliable description of the dynamic behavior of the adsorption thermal energy storage unit is achieved. The model is used to study and benchmark the performance of adsorption thermal energy storage combined with cogeneration for batch process energy supply. As benchmark, we consider both a peak boiler and latent thermal energy storage based on a phase change material. Beer brewing is considered as an example of an industrial batch process. The study shows that adsorption thermal energy storage has the potential to increase energy efficiency significantly; primary energy consumption can be reduced by up to 25%. However, successful integration of adsorption thermal storage requires appropriate integration of low grade heat: Preferentially, low grade heat is available at times of discharging and in demand when charging the storage unit. Thus, adsorption thermal energy storage is most beneficial if applied to a batch process with heat demands on several temperature levels. - Highlights: • A highly efficient energy supply for industrial batch processes is presented. • Adsorption thermal energy storage (TES) is analyzed in experiment and simulation. • Adsorption TES can outperform both peak boilers and latent TES. • Performance of adsorption TES strongly depends on low grade heat temperature.

  10. Multi-enzyme Process Modeling

    DEFF Research Database (Denmark)

    Andrade Santacoloma, Paloma de Gracia

    are affected (in a positive or negative way) by the presence of the other enzymes and compounds in the media. In this thesis the concept of multi-enzyme in-pot term is adopted for processes that are carried out by the combination of enzymes in a single reactor and implemented at pilot or industrial scale...... features of the process and provides the information required to structure the process model by using a step-by-step procedure with the required tools and methods. In this way, this framework increases efficiency of the model development process with respect to time and resources needed (fast and effective....... In this way the model parameters that drives the main dynamic behavior can be identified and thus a better understanding of this type of processes. In order to develop, test and verify the methodology, three case studies were selected, specifically the bi-enzyme process for the production of lactobionic acid...

  11. Sato Processes in Default Modeling

    DEFF Research Database (Denmark)

    Kokholm, Thomas; Nicolato, Elisa

    -change of a homogeneous Levy process. While the processes in these two classes share the same average behavior over time, the associated intensities exhibit very different properties. Concrete specifications are calibrated to data on the single names included in the iTraxx Europe index. The performances are compared......In reduced form default models, the instantaneous default intensity is classically the modeling object. Survival probabilities are then given by the Laplace transform of the cumulative hazard defined as the integrated intensity process. Instead, recent literature has shown a tendency towards...... specifying the cumulative hazard process directly. Within this framework we present a new model class where cumulative hazards are described by self-similar additive processes, also known as Sato processes. Furthermore we also analyze specifications obtained via a simple deterministic time...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1996-08-01

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

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

    International Nuclear Information System (INIS)

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

    2010-01-01

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

  14. A METHOD FOR EXERGY ANALYSIS OF SUGARCANE BAGASSE BOILERS

    Directory of Open Access Journals (Sweden)

    CORTEZ L.A.B.

    1998-01-01

    Full Text Available This work presents a method to conduct a thermodynamic analysis of sugarcane bagasse boilers. The method is based on the standard and actual reactions which allows the calculation of the enthalpies of each process subequation and the exergies of each of the main flowrates participating in the combustion. The method is presented using an example with real data from a sugarcane bagasse boiler. A summary of the results obtained is also presented together based on the 1st Law of Thermodynamics analysis, the exergetic efficiencies, and the irreversibility rates. The method presented is very rigorous with respect to data consistency, particularly for the flue gas composition.

  15. Markov Decision Process Measurement Model.

    Science.gov (United States)

    LaMar, Michelle M

    2018-03-01

    Within-task actions can provide additional information on student competencies but are challenging to model. This paper explores the potential of using a cognitive model for decision making, the Markov decision process, to provide a mapping between within-task actions and latent traits of interest. Psychometric properties of the model are explored, and simulation studies report on parameter recovery within the context of a simple strategy game. The model is then applied to empirical data from an educational game. Estimates from the model are found to correlate more strongly with posttest results than a partial-credit IRT model based on outcome data alone.

  16. 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.

  17. Social Models: Blueprints or Processes?

    Science.gov (United States)

    Little, Graham R.

    1981-01-01

    Discusses the nature and implications of two different models for societal planning: (1) the problem-solving process approach based on Karl Popper; and (2) the goal-setting "blueprint" approach based on Karl Marx. (DC)

  18. Simple Models for Process Control

    Czech Academy of Sciences Publication Activity Database

    Gorez, R.; Klán, Petr

    2011-01-01

    Roč. 22, č. 2 (2011), s. 58-62 ISSN 0929-2268 Institutional research plan: CEZ:AV0Z10300504 Keywords : process model s * PID control * second order dynamics Subject RIV: JB - Sensors, Measurment, Regulation

  19. Failure Analysis of 600 MW Supercritical Boiler Water Wall

    OpenAIRE

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

    2013-01-01

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

  20. Model feedstock supply processing plants

    Directory of Open Access Journals (Sweden)

    V. M. Bautin

    2013-01-01

    Full Text Available The model of raw providing the processing enterprises entering into vertically integrated structure on production and processing of dairy raw materials, differing by an orientation on achievement of cumulative effect by the integrated structure acting as criterion function which maximizing is reached by optimization of capacities, volumes of deliveries of raw materials and its qualitative characteristics, costs of industrial processing of raw materials and demand for dairy production is developed.

  1. assessment of some performance characteristics of refuse boiler ...

    African Journals Online (AJOL)

    TIMZY

    2013-07-02

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

  2. Sato Processes in Default Modeling

    DEFF Research Database (Denmark)

    Kokholm, Thomas; Nicolato, Elisa

    2010-01-01

    In reduced form default models, the instantaneous default intensity is the classical modeling object. Survival probabilities are then given by the Laplace transform of the cumulative hazard defined as the integrated intensity process. Instead, recent literature tends to specify the cumulative haz...

  3. Sato Processes in Default Modeling

    DEFF Research Database (Denmark)

    Kokholm, Thomas; Nicolato, Elisa

    In reduced form default models, the instantaneous default intensity is classically the modeling object. Survival probabilities are then given by the Laplace transform of the cumulative hazard defined as the integrated intensity process. Instead, recent literature has shown a tendency towards...

  4. Biomass boiler still best choice

    International Nuclear Information System (INIS)

    Wallace, Paula

    2014-01-01

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

  5. Metrics for Business Process Models

    Science.gov (United States)

    Mendling, Jan

    Up until now, there has been little research on why people introduce errors in real-world business process models. In a more general context, Simon [404] points to the limitations of cognitive capabilities and concludes that humans act rationally only to a certain extent. Concerning modeling errors, this argument would imply that human modelers lose track of the interrelations of large and complex models due to their limited cognitive capabilities and introduce errors that they would not insert in a small model. A recent study by Mendling et al. [275] explores in how far certain complexity metrics of business process models have the potential to serve as error determinants. The authors conclude that complexity indeed appears to have an impact on error probability. Before we can test such a hypothesis in a more general setting, we have to establish an understanding of how we can define determinants that drive error probability and how we can measure them.

  6. Computer Modelling of Dynamic Processes

    Directory of Open Access Journals (Sweden)

    B. Rybakin

    2000-10-01

    Full Text Available Results of numerical modeling of dynamic problems are summed in the article up. These problems are characteristic for various areas of human activity, in particular for problem solving in ecology. The following problems are considered in the present work: computer modeling of dynamic effects on elastic-plastic bodies, calculation and determination of performances of gas streams in gas cleaning equipment, modeling of biogas formation processes.

  7. Multivariable robust adaptive sliding mode control of an industrial boiler-turbine in the presence of modeling imprecisions and external disturbances: A comparison with type-I servo controller.

    Science.gov (United States)

    Ghabraei, Soheil; Moradi, Hamed; Vossoughi, Gholamreza

    2015-09-01

    To guarantee the safety and efficient performance of the power plant, a robust controller for the boiler-turbine unit is needed. In this paper, a robust adaptive sliding mode controller (RASMC) is proposed to control a nonlinear multi-input multi-output (MIMO) model of industrial boiler-turbine unit, in the presence of unknown bounded uncertainties and external disturbances. To overcome the coupled nonlinearities and investigate the zero dynamics, input-output linearization is performed, and then the new decoupled inputs are derived. To tackle the uncertainties and external disturbances, appropriate adaption laws are introduced. For constructing the RASMC, suitable sliding surface is considered. To guarantee the sliding motion occurrence, appropriate control laws are constructed. Then the robustness and stability of the proposed RASMC is proved via Lyapunov stability theory. To compare the performance of the purposed RASMC with traditional control schemes, a type-I servo controller is designed. To evaluate the performance of the proposed control schemes, simulation studies on nonlinear MIMO dynamic system in the presence of high frequency bounded uncertainties and external disturbances are conducted and compared. Comparison of the results reveals the superiority of proposed RASMC over the traditional control schemes. RAMSC acts efficiently in disturbance rejection and keeping the system behavior in desirable tracking objectives, without the existence of unstable quasi-periodic solutions. Copyright © 2015 ISA. Published by Elsevier Ltd. All rights reserved.

  8. Modelling Hospital Materials Management Processes

    Directory of Open Access Journals (Sweden)

    Raffaele Iannone

    2013-06-01

    integrated and detailed analysis and description model for hospital materials management data and tasks, which is able to tackle information from patient requirements to usage, from replenishment requests to supplying and handling activities. The model takes account of medical risk reduction, traceability and streamlined processes perspectives. Second, the paper translates this information into a business process model and mathematical formalization.The study provides a useful guide to the various relevant technology‐related, management and business issues, laying the foundations of an efficient reengineering of the supply chain to reduce healthcare costs and improve the quality of care.

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

    International Nuclear Information System (INIS)

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

    1986-01-01

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

  10. Declarative modeling for process supervision

    International Nuclear Information System (INIS)

    Leyval, L.

    1989-01-01

    Our work is a contribution to computer aided supervision of continuous processes. It is inspired by an area of Artificial Intelligence: qualitative physics. Here, supervision is based on a model which continuously provides operators with a synthetic view of the process; but this model is founded on general principles of control theory rather than on physics. It involves concepts such as high gain or small time response. It helps in linking temporally the evolution of various variables. Moreover, the model provides predictions of the future behaviour of the process, which allows action advice and alarm filtering. This should greatly reduce the famous cognitive overload associated to any complex and dangerous evolution of the process

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

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

  12. 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

  13. Modeling of biopharmaceutical processes. Part 2: Process chromatography unit operation

    DEFF Research Database (Denmark)

    Kaltenbrunner, Oliver; McCue, Justin; Engel, Philip

    2008-01-01

    Process modeling can be a useful tool to aid in process development, process optimization, and process scale-up. When modeling a chromatography process, one must first select the appropriate models that describe the mass transfer and adsorption that occurs within the porous adsorbent. The theoret......Process modeling can be a useful tool to aid in process development, process optimization, and process scale-up. When modeling a chromatography process, one must first select the appropriate models that describe the mass transfer and adsorption that occurs within the porous adsorbent...

  14. Neuroscientific Model of Motivational Process

    Science.gov (United States)

    Kim, Sung-il

    2013-01-01

    Considering the neuroscientific findings on reward, learning, value, decision-making, and cognitive control, motivation can be parsed into three sub processes, a process of generating motivation, a process of maintaining motivation, and a process of regulating motivation. I propose a tentative neuroscientific model of motivational processes which consists of three distinct but continuous sub processes, namely reward-driven approach, value-based decision-making, and goal-directed control. Reward-driven approach is the process in which motivation is generated by reward anticipation and selective approach behaviors toward reward. This process recruits the ventral striatum (reward area) in which basic stimulus-action association is formed, and is classified as an automatic motivation to which relatively less attention is assigned. By contrast, value-based decision-making is the process of evaluating various outcomes of actions, learning through positive prediction error, and calculating the value continuously. The striatum and the orbitofrontal cortex (valuation area) play crucial roles in sustaining motivation. Lastly, the goal-directed control is the process of regulating motivation through cognitive control to achieve goals. This consciously controlled motivation is associated with higher-level cognitive functions such as planning, retaining the goal, monitoring the performance, and regulating action. The anterior cingulate cortex (attention area) and the dorsolateral prefrontal cortex (cognitive control area) are the main neural circuits related to regulation of motivation. These three sub processes interact with each other by sending reward prediction error signals through dopaminergic pathway from the striatum and to the prefrontal cortex. The neuroscientific model of motivational process suggests several educational implications with regard to the generation, maintenance, and regulation of motivation to learn in the learning environment. PMID:23459598

  15. Neuroscientific model of motivational process.

    Science.gov (United States)

    Kim, Sung-Il

    2013-01-01

    Considering the neuroscientific findings on reward, learning, value, decision-making, and cognitive control, motivation can be parsed into three sub processes, a process of generating motivation, a process of maintaining motivation, and a process of regulating motivation. I propose a tentative neuroscientific model of motivational processes which consists of three distinct but continuous sub processes, namely reward-driven approach, value-based decision-making, and goal-directed control. Reward-driven approach is the process in which motivation is generated by reward anticipation and selective approach behaviors toward reward. This process recruits the ventral striatum (reward area) in which basic stimulus-action association is formed, and is classified as an automatic motivation to which relatively less attention is assigned. By contrast, value-based decision-making is the process of evaluating various outcomes of actions, learning through positive prediction error, and calculating the value continuously. The striatum and the orbitofrontal cortex (valuation area) play crucial roles in sustaining motivation. Lastly, the goal-directed control is the process of regulating motivation through cognitive control to achieve goals. This consciously controlled motivation is associated with higher-level cognitive functions such as planning, retaining the goal, monitoring the performance, and regulating action. The anterior cingulate cortex (attention area) and the dorsolateral prefrontal cortex (cognitive control area) are the main neural circuits related to regulation of motivation. These three sub processes interact with each other by sending reward prediction error signals through dopaminergic pathway from the striatum and to the prefrontal cortex. The neuroscientific model of motivational process suggests several educational implications with regard to the generation, maintenance, and regulation of motivation to learn in the learning environment.

  16. 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...

  17. 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...

  18. Fluidized bed boiler feed system

    Science.gov (United States)

    Jones, Brian C.

    1981-01-01

    A fluidized bed boiler feed system for the combustion of pulverized coal. Coal is first screened to separate large from small particles. Large particles of coal are fed directly to the top of the fluidized bed while fine particles are first mixed with recycled char, preheated, and then fed into the interior of the fluidized bed to promote char burnout and to avoid elutriation and carryover.

  19. Active brickworks - phase I[For application in biofuel boilers]; Aktiva murverk - etapp I

    Energy Technology Data Exchange (ETDEWEB)

    Wrangensten, Lars; Schuster, Robert; Ingman, Rolf; Sendelius, Mikael; Ehleskog, Rickard [AaF-Energikonsult AB, Stockholm (Sweden)

    2003-10-01

    This report is the first step of the R and D project 'Active brickworks' within the program 'Possibilities to improve the operation conditions in industrial bark boilers by optimised combustion control'. Good high temperature resistance is one of the major characteristics of ceramics. They are based on quartz and aluminium oxide, an attachment component (acid or cement) and also different types of additives which, together with the heating treatment, gives the ceramic materials their features. The brickwork in a boiler has several assignments. First of all resistance to corrosion, erosion and protection against fouling of the water tube walls, but also to significant affect the combustion process by energy saving features and heating radiation. This project has been focused on the last named features, namely to be able to make a more active choice of brickwork in order to utilise the ceramic features and hereby making it possible to lower the combustion process emissions. The material samples received from the manufactures have been tested in a small-scale laboratory rig. Features investigated are emissivity/reflection, heat conductivity and heat capacity. Mathematic simulations have also been performed with a representative type boiler model in order to make conclusions concerning how the results can be transformed to and applied in a real full-scale boiler. The most important designing case for ceramics in bark boilers is when boiler load rapidly increases or during a fast fuel moisture change from dry to wet fuel. It has been concluded in the study that that the ceramic walls in a boiler should be divided into different layers. The outer layer in the ceiling and sidewalls of the drying zone must consist of highly insulating material in order to get a high temperature of heating surfaces close to the furnace. To store heat during load transients the heating surfaces must have high emissivity factor and good heating capacity. From this point of

  20. ECONOMIC MODELING PROCESSES USING MATLAB

    Directory of Open Access Journals (Sweden)

    Anamaria G. MACOVEI

    2008-06-01

    Full Text Available To study economic phenomena and processes using mathem atical modeling, and to determine the approximatesolution to a problem we need to choose a method of calculation and a numerical computer program, namely thepackage of programs MatLab. Any economic process or phenomenon is a mathematical description of h is behavior,and thus draw up an economic and mathematical model that has the following stages: formulation of the problem, theanalysis process modeling, the production model and design verification, validation and implementation of the model.This article is presented an economic model and its modeling is using mathematical equations and software packageMatLab, which helps us approximation effective solution. As data entry is considered the net cost, the cost of direct andtotal cost and the link between them. I presented the basic formula for determining the total cost. Economic modelcalculations were made in MatLab software package and with graphic representation of its interpretation of the resultsachieved in terms of our specific problem.

  1. Path modeling and process control

    DEFF Research Database (Denmark)

    Høskuldsson, Agnar; Rodionova, O.; Pomerantsev, A.

    2007-01-01

    and having three or more stages. The methods are applied to a process control of a multi-stage production process having 25 variables and one output variable. When moving along the process, variables change their roles. It is shown how the methods of path modeling can be applied to estimate variables...... be performed regarding the foreseeable output property y, and with respect to an admissible range of correcting actions for the parameters of the next stage. In this paper the basic principles of path modeling is presented. The mathematics is presented for processes having only one stage, having two stages...... of the next stage with the purpose of obtaining optimal or almost optimal quality of the output variable. An important aspect of the methods presented is the possibility of extensive graphic analysis of data that can provide the engineer with a detailed view of the multi-variate variation in data....

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-07-01

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

  3. Process Models for Security Architectures

    Directory of Open Access Journals (Sweden)

    Floarea NASTASE

    2006-01-01

    Full Text Available This paper presents a model for an integrated security system, which can be implemented in any organization. It is based on security-specific standards and taxonomies as ISO 7498-2 and Common Criteria. The functionalities are derived from the classes proposed in the Common Criteria document. In the paper we present the process model for each functionality and also we focus on the specific components.

  4. 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)

  5. 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)

  6. 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.

  7. 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.

  8. CHP as a Boiler Replacement Opportunity (Webinar) – April 30, 2013

    Science.gov (United States)

    This webinar provides information about the benefits of replacing a boiler with a CHP system, describes CHP project analysis and delivery processes, and highlights a case study at Penn State University.

  9. Mathematical modelling in economic processes.

    Directory of Open Access Journals (Sweden)

    L.V. Kravtsova

    2008-06-01

    Full Text Available In article are considered a number of methods of mathematical modelling of economic processes and opportunities of use of spreadsheets Excel for reception of the optimum decision of tasks or calculation of financial operations with the help of the built-in functions.

  10. Visualizing the process of process modeling with PPMCharts

    NARCIS (Netherlands)

    Claes, J.; Vanderfeesten, I.T.P.; Pinggera, J.; Reijers, H.A.; Weber, B.; Poels, G.; La Rosa, M.; Soffer, P.

    2013-01-01

    In the quest for knowledge about how to make good process models, recent research focus is shifting from studying the quality of process models to studying the process of process modeling (often abbreviated as PPM) itself. This paper reports on our efforts to visualize this specific process in such

  11. 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.

  12. 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

  13. Neuroscientific Model of Motivational Process

    Directory of Open Access Journals (Sweden)

    Sung-Il eKim

    2013-03-01

    Full Text Available Considering the neuroscientific findings on reward, learning, value, decision-making, and cognitive control, motivation can be parsed into three subprocesses, a process of generating motivation, a process of maintaining motivation, and a process of regulating motivation. I propose a tentative neuroscientific model of motivational processes which consists of three distinct but continuous subprocesses, namely reward-driven approach, value-based decision making, and goal-directed control. Reward-driven approach is the process in which motivation is generated by reward anticipation and selective approach behaviors toward reward. This process recruits the ventral striatum (reward area in which basic stimulus-action association is formed, and is classified as an automatic motivation to which relatively less attention is assigned. By contrast, value-based decision making is the process of evaluating various outcomes of actions, learning through positive prediction error, and calculating the value continuously. The striatum and the orbitofrontal cortex (valuation area play crucial roles in sustaining motivation. Lastly, the goal-directed control is the process of regulating motivation through cognitive control to achieve goals. This consciously controlled motivation is associated with higher-level cognitive functions such as planning, retaining the goal, monitoring the performance, and regulating action. The anterior cingulate cortex (attention area and the dorsolateral prefrontal cortex (cognitive control area are the main neural circuits related to regulation of motivation. These three subprocesses interact with each other by sending reward prediction error signals through dopaminergic pathway from the striatum and to the prefrontal cortex. The neuroscientific model of motivational process suggests several educational implications with regard to the generation, maintenance, and regulation of motivation to learn in the learning environment.

  14. Integrated Site Model Process Model Report

    International Nuclear Information System (INIS)

    Booth, T.

    2000-01-01

    The Integrated Site Model (ISM) provides a framework for discussing the geologic features and properties of Yucca Mountain, which is being evaluated as a potential site for a geologic repository for the disposal of nuclear waste. The ISM is important to the evaluation of the site because it provides 3-D portrayals of site geologic, rock property, and mineralogic characteristics and their spatial variabilities. The ISM is not a single discrete model; rather, it is a set of static representations that provide three-dimensional (3-D), computer representations of site geology, selected hydrologic and rock properties, and mineralogic-characteristics data. These representations are manifested in three separate model components of the ISM: the Geologic Framework Model (GFM), the Rock Properties Model (RPM), and the Mineralogic Model (MM). The GFM provides a representation of the 3-D stratigraphy and geologic structure. Based on the framework provided by the GFM, the RPM and MM provide spatial simulations of the rock and hydrologic properties, and mineralogy, respectively. Functional summaries of the component models and their respective output are provided in Section 1.4. Each of the component models of the ISM considers different specific aspects of the site geologic setting. Each model was developed using unique methodologies and inputs, and the determination of the modeled units for each of the components is dependent on the requirements of that component. Therefore, while the ISM represents the integration of the rock properties and mineralogy into a geologic framework, the discussion of ISM construction and results is most appropriately presented in terms of the three separate components. This Process Model Report (PMR) summarizes the individual component models of the ISM (the GFM, RPM, and MM) and describes how the three components are constructed and combined to form the ISM

  15. The Technology Introduction of Chain Boiler Energy Conservation Transformation

    Science.gov (United States)

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

    2017-12-01

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

  16. Elevated temperature failures in boiler tubes - case studies

    International Nuclear Information System (INIS)

    Gowrisankar, I.; Bandyopadhyay, G.

    1989-01-01

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

  17. Investigating the Process of Process Modeling with Eye Movement Analysis

    OpenAIRE

    Pinggera, Jakob; Furtner, Marco; Martini, Markus; Sachse, Pierre; Reiter, Katharina; Zugal, Stefan; Weber, Barbara

    2015-01-01

    Research on quality issues of business process models has recently begun to explore the process of creating process models by analyzing the modeler's interactions with the modeling environment. In this paper we aim to complement previous insights on the modeler's modeling behavior with data gathered by tracking the modeler's eye movements when engaged in the act of modeling. We present preliminary results and outline directions for future research to triangulate toward a more comprehensive un...

  18. Welding process modelling and control

    Science.gov (United States)

    Romine, Peter L.; Adenwala, Jinen A.

    1993-01-01

    The research and analysis performed, and software developed, and hardware/software recommendations made during 1992 in development of the PC-based data acquisition system for support of Welding Process Modeling and Control is reported. A need was identified by the Metals Processing Branch of NASA Marshall Space Flight Center, for a mobile data aquisition and analysis system, customized for welding measurement and calibration. Several hardware configurations were evaluated and a PC-based system was chosen. The Welding Measurement System (WMS) is a dedicated instrument, strictly for the use of data aquisition and analysis. Although the WMS supports many of the functions associated with the process control, it is not the intention for this system to be used for welding process control.

  19. Numerical Research of Nitrogen Oxides Formation for Justification of Modernization of P-49 Nazarovsky State District Power Plant Boiler on the Low-temperature Swirl Technology of Burning

    Science.gov (United States)

    Trinchenko, A. A.; Paramonov, A. P.; Skouditskiy, V. E.; Anoshin, R. G.

    2017-11-01

    Compliance with increasingly stringent normative requirements to the level of pollutants emissions when using organic fuel in the energy sector as a main source of heat, demands constant improvement of the boiler and furnace equipment and the power equipment in general. The requirements of the current legislation in the field of environmental protection prescribe compliance with established emission standards for both new construction and the improvement of energy equipment. The paper presents the results of numerical research of low-temperature swirl burning in P-49 Nazarovsky state district power plant boiler. On the basis of modern approaches of the diffusion and kinetic theory of burning and the analysis physical and chemical processes of a fuel chemically connected energy transition in thermal, generation and transformation of gas pollutants, the technological method of nitrogen oxides decomposition on the surface of carbon particles with the formation of environmentally friendly carbonic acid and molecular nitrogen is considered during the work of low-temperature swirl furnace. With the use of the developed model, methodology and computer program, variant calculations of the combustion process were carried out and a quantitative estimate of the emission level of the nitrogen oxides of the boiler being modernized. The simulation results the and the experimental data obtained during the commissioning and balance tests of the P-49 boiler with a new furnace are confirmed that the organization of swirl combustion has allowed to increase the efficiency of work, to reduce slagging, to significantly reduce nitrogen oxide emissions, to improve ignition and burnout of fuel.

  20. Analysis of emission reduction strategies for power boilers in the US pulp and paper industry

    Data.gov (United States)

    U.S. Environmental Protection Agency — This paper first presents the background information for UISIS-PNP model by discussing different types of boilers installed throughout the pulp and paper sector, the...

  1. Hydrogen embrittlement corrosion failure of water wall tubes in large power station boilers

    International Nuclear Information System (INIS)

    Mathur, P.K.

    1981-01-01

    In the present paper, causes and mechanism of hydrogen embrittlement failure of water wall tubes in high pressure boilers have been discussed. A low pH boiler water environment, produced as a result of condenser leakage or some other type of system contamination and presence of internal metal oxide deposits, which permit boiler water solids to concentrate during the process of steam generation, have been ascribed to accelerate the formation of local corrosion cells conducive for acid attack resulting in hydrogen damage failure of water wall tubes. (author)

  2. PIV measurements of the turbulence integral length scale on cold combustion flow field of tangential firing boiler

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Wen-fei; Xie, Jing-xing; Gong, Zhi-jun; Li, Bao-wei [Inner Mongolia Univ. of Science and Technology, Baotou (China). Inner Mongolia Key Lab. for Utilization of Bayan Obo Multi-Metallic Resources: Elected State Key Lab.

    2013-07-01

    The process of the pulverized coal combustion in tangential firing boiler has prominent significance on improving boiler operation efficiency and reducing NO{sub X} emission. This paper aims at researching complex turbulent vortex coherent structure formed by the four corners jets in the burner zone, a cold experimental model of tangential firing boiler has been built. And by employing spatial correlation analysis method and PIV (Particle Image Velocimetry) technique, the law of Vortex scale distribution on the three typical horizontal layers of the model based on the turbulent Integral Length Scale (ILS) has been researched. According to the correlation analysis of ILS and the temporal average velocity, it can be seen that the turbulent vortex scale distribution in the burner zone of the model is affected by both jet velocity and the position of wind layers, and is not linear with the variation of jet velocity. The vortex scale distribution of the upper primary air is significantly different from the others. Therefore, studying the ILS of turbulent vortex integral scale is instructive to high efficiency cleaning combustion of pulverized coal in theory.

  3. 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

  4. Staged fluidized-bed coal combustor for boiler retrofit

    International Nuclear Information System (INIS)

    Rehmat, A.; Dorfman, L.; Shibayama, G.; Waibel, R.

    1991-01-01

    The Advanced Staged Fluidized-Bed Coal Combustion System (ASC) is a novel clean coal technology for either coal-fired repowering of existing boilers or for incremental power generation using combined-cycle gas turbines. This new technology combines staged combustion for gaseous emission control, in-situ sulfur capture, and an ash agglomeration/vitrification process for the agglomeration/vitrification of ash and spent sorbent, thus rendering solid waste environmentally benign. The market for ASC is expected to be for clean coal-fired repowering of generating units up to 250 MW, especially for units where space is limited. The expected tightening of the environmental requirements on leachable solids residue by-products could considerably increase the marketability for ASC. ASC consists of modular low-pressure vessels in which coal is partially combusted and gasified using stacked fluidized-bed processes to produce low-to-medium-Btu, high-temperature gas. This relatively clean fuel gas is used to repower/refuel existing pulverized-coal, natural gas, or oil-fired boilers using bottom firing and reburning techniques. The benefits of ASC coal-fired repowering include the ability to repower boilers without obtaining additional space while meeting the more stringent environmental requirements of the future. Low NO x , SO x , and particulate levels are expected while a nonleachable solid residue with trace metal encapsulation is produced. ASC also minimizes boiler modification and life-extension expenditures. Repowered efficiencies can be restored to the initial operating plant efficiency, and the existing boiler capacity can be increased by 10%. Preliminary cost estimates indicate that ASC will have up to a $250/kW capital cost advantage over existing coal-fired repowering options. 4 figs., 4 tabs

  5. Advanced oxidation processes: overall models

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, M. [Univ. de los Andes, Escuela Basica de Ingenieria, La Hechicera, Merida (Venezuela); Curco, D.; Addardak, A.; Gimenez, J.; Esplugas, S. [Dept. de Ingenieria Quimica. Univ. de Barcelona, Barcelona (Spain)

    2003-07-01

    Modelling AOPs implies to consider all the steps included in the process, that means, mass transfer, kinetic (reaction) and luminic steps. In this way, recent works develop models which relate the global reaction rate to catalyst concentration and radiation absorption. However, the application of such models requires to know what is the controlling step for the overall process. In this paper, a simple method is explained which allows to determine the controlling step. Thus, it is assumed that reactor is divided in two hypothetical zones (dark and illuminated), and according to the experimental results, obtained by varying only the reaction volume, it can be decided if reaction occurs only in the illuminated zone or in the all reactor, including dark zone. The photocatalytic degradation of phenol, by using titania degussa P-25 as catalyst, is studied as reaction model. The preliminary results obtained are presented here, showing that it seems that, in this case, reaction only occurs in the illuminated zone of photoreactor. A model is developed to explain this behaviour. (orig.)

  6. Model for amorphous aggregation processes

    Science.gov (United States)

    Stranks, Samuel D.; Ecroyd, Heath; van Sluyter, Steven; Waters, Elizabeth J.; Carver, John A.; von Smekal, Lorenz

    2009-11-01

    The amorphous aggregation of proteins is associated with many phenomena, ranging from the formation of protein wine haze to the development of cataract in the eye lens and the precipitation of recombinant proteins during their expression and purification. While much literature exists describing models for linear protein aggregation, such as amyloid fibril formation, there are few reports of models which address amorphous aggregation. Here, we propose a model to describe the amorphous aggregation of proteins which is also more widely applicable to other situations where a similar process occurs, such as in the formation of colloids and nanoclusters. As first applications of the model, we have tested it against experimental turbidimetry data of three proteins relevant to the wine industry and biochemistry, namely, thaumatin, a thaumatinlike protein, and α -lactalbumin. The model is very robust and describes amorphous experimental data to a high degree of accuracy. Details about the aggregation process, such as shape parameters of the aggregates and rate constants, can also be extracted.

  7. EFFICIENCY IMPROVEMENT IN INDUSTRIAL BOILER BY FLUE GAS DUCT INSULATION

    OpenAIRE

    Sanjay H. Zala

    2017-01-01

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

  8. FY 2000 report on the potential survey of the environmental friendly type coal utilization system. Survey for digging up items for the model project on spread type circulating fluid bed boilers in China; 2000 nendo chosa hokokusho. Kankyo chowagata sekitan riyo system kanosei chosa. Chugoku ni okeru fukyugata junkan ryudo yukaboira setsubi model jigyo no anken hakkutsu chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-09-01

    For the purpose of spreading/promoting circulating fluidized bed boilers in China, survey was conducted on the confirmation of effectiveness of implementation of the model project on spread type circulating fluidized bed boilers and the appropriateness of the sites proposed for implementation. As to the model of spread type 35t/h-CFB boilers, local products are more integrated into it, taking cost reduction of equipment and secure performance/quality into consideration, and the wider-ranging technical guidance/transfer are conducted also in design/production. In China, where environmental regulations are not strict, and there are many restrictions on funds, the size of the initial investment is an important element for selection of type. Further, the market is very big, about 200 units/year. It is highly possible to realize the competitive cost level by the quantity production effect by increasing local production. Two companies, Southeast Electrochemical Co. and Fujian Prime Pharmaceutical Group Co., which were proposed as sites are financially good and are achieving substantial results. Both companies are located in the urban area, and therefore, environmental measures should urgently be taken, and PR activities for spread are highly effective. It was confirmed that the companies were fully appropriate as sites proposed for the spread type model project. (NEDO)

  9. Methodology for the physical and chemical exergetic analysis of steam boilers

    International Nuclear Information System (INIS)

    Ohijeagbon, Idehai O.; Waheed, M. Adekojo; Jekayinfa, Simeon O.

    2013-01-01

    This paper presents a framework of thermodynamic, energy and exergy, analyses of industrial steam boilers. Mass, energy, and exergy analysis were used to develop a methodology for evaluating thermodynamic properties, energy and exergy input and output resources in industrial steam boilers. Determined methods make available an analytic procedure for the physical and chemical exergetic analysis of steam boilers for appropriate applications. The energy and exergy efficiencies obtained for the entire boiler was 69.56% and 38.57% at standard reference state temperature of 25 °C for an evaporation ratio of 12. Chemical exergy of the material streams was considered to offer a more comprehensive detail on energy and exergy resource allocation and losses of the processes in a steam boiler. - Highlights: ► We evaluated thermodynamic properties and performance variables associated with material streams. ► We analysed resources allocation, and magnitude of exergetic losses in steam boilers. ► Chemical exergy of material streams contributed to improved exergy values. ► High operational parameter will lead to higher boiler exergy. ► Exergy destroyed was higher in the combustion as against the heat exchanging unit

  10. Research report of FY 1997 on the environmentally acceptable coal utilization system introduction support project. Follow-up project on circulating fluidized bed boiler introduction (Calaca Batangas Thermal Power Station); 1997 nendo chosa hokokusho. Kankyo chowagata sekitan riyo system donyu shien jigyo (junkan ryudosho boiler ni kakawaru follow up jigyo (Calaca Batangas karyoku hatsudensho))

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    For the follow-up project, to promote the diffusion of results of the clean coal technology (CCT) model projects, experts of circulating fluidized bed boilers were dispatched, to guide and advise for the operation of facilities introduced in these projects. The purpose of these projects is to diffuse the CCTs, and to support the promotion of environmental measures. Some guidance and advice about operation processes, data processing, operation regulation, maintenance, and boiler maintenance works were provided to the Ministry of Energy and Electric Power Corporation of the Philippines. Semirara, Malangas, and Samar coals in the Philippines were used for the tests. The boiler facilities could be operated by Philippine operators themselves. Based on the guidance and advice about operation processes, combustion tests using various Philippine coals were also planned and conducted by themselves. The maintenance techniques were transferred to Philippine operators through the inspection, repair and advice. The Philippine side understood the technologies well, and the circulating fluidized bed boiler technology was independently educated in the Philippines. 23 figs., 16 tabs.

  11. Fiscal 2000 achievement report. Model project for international energy consumption efficiency improvement (Model project for improvement of boiler and turbine efficiency); 2000 nendo seika hokoku. Kokusai energy shohi koritsuka tou model jigyo (Boira tabin koritsu kojo model jigyo)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-12-01

    A project was implemented for Japan to transfer its energy conservation technologies for helping Indonesia conserve energy and reduce CO2 emissions, which occurred at Muara Karang Thermal Power Plant of an Indonesian power company named PT PJB. Items to be introduced are condenser tubes (material change from cupro-nickel to titanium), ball cleaning equipment, turbine gland seal improvement, air preheater improvement, thermal efficiency management system, and so forth. In this fiscal year, turbine gland seals and air preheater elements were manufactured, and the thermal efficiency management system was designed. As an dissemination activity, 10 engineers were invited to Japan from the Indonesian Ministry of Energy and Mineral Resources, PT PLN, and PT PJB. They attended a training program lasting approximately two weeks, which included study tours to the factories actually building the equipment to be introduced and field/classroom training/education on thermal efficiency management and others. The engineers actively performed their boiler improvement work back in Indonesia. (NEDO)

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Jagodzińska Katarzyna

    2016-01-01

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

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

    International Nuclear Information System (INIS)

    Compton, M.; Rezaie, B.

    2017-01-01

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

  15. Economic evaluation of a coal fired boiler

    International Nuclear Information System (INIS)

    Briem, J.J.

    1983-01-01

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

  16. 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...

  17. 29 CFR 1915.162 - Ship's boilers.

    Science.gov (United States)

    2010-07-01

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

  18. Probabilistic evaluation of process model matching techniques

    NARCIS (Netherlands)

    Kuss, Elena; Leopold, Henrik; van der Aa, Han; Stuckenschmidt, Heiner; Reijers, Hajo A.

    2016-01-01

    Process model matching refers to the automatic identification of corresponding activities between two process models. It represents the basis for many advanced process model analysis techniques such as the identification of similar process parts or process model search. A central problem is how to

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

    NARCIS (Netherlands)

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

    2013-01-01

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

  20. 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)

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

    Energy Technology Data Exchange (ETDEWEB)

    Levasseur, Armand

    2014-04-30

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

  2. Mathematical modeling of biological processes

    CERN Document Server

    Friedman, Avner

    2014-01-01

    This book on mathematical modeling of biological processes includes a wide selection of biological topics that demonstrate the power of mathematics and computational codes in setting up biological processes with a rigorous and predictive framework. Topics include: enzyme dynamics, spread of disease, harvesting bacteria, competition among live species, neuronal oscillations, transport of neurofilaments in axon, cancer and cancer therapy, and granulomas. Complete with a description of the biological background and biological question that requires the use of mathematics, this book is developed for graduate students and advanced undergraduate students with only basic knowledge of ordinary differential equations and partial differential equations; background in biology is not required. Students will gain knowledge on how to program with MATLAB without previous programming experience and how to use codes in order to test biological hypothesis.

  3. Feasibility Study of Correcting Circuit Scheme for Automatic Control System of Total Air in Boiler

    Directory of Open Access Journals (Sweden)

    V. I. Nazarov

    2013-01-01

    Full Text Available The paper contains results of investigations on dynamic characteristics automatic control system (ACS for total air consumption (TAC in a boiler with corrections for О2 and СО. From transition process point of view the ACS TAC with correction for СО is considered as the most optimum one as with disturbance attack on fuel expenditure so discharging beyond boiler furnace.

  4. Simulation of pulverized coal fired boiler: reaction chamber

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-06-15

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

  5. Modeling pellet impact drilling process

    Science.gov (United States)

    Kovalyov, A. V.; Ryabchikov, S. Ya; Isaev, Ye D.; Ulyanova, O. S.

    2016-03-01

    The paper describes pellet impact drilling which could be used to increase the drilling speed and the rate of penetration when drilling hard rocks. Pellet impact drilling implies rock destruction by metal pellets with high kinetic energy in the immediate vicinity of the earth formation encountered. The pellets are circulated in the bottom hole by a high velocity fluid jet, which is the principle component of the ejector pellet impact drill bit. The experiments conducted has allowed modeling the process of pellet impact drilling, which creates the scientific and methodological basis for engineering design of drilling operations under different geo-technical conditions.

  6. Integrated modelling in materials and process technology

    DEFF Research Database (Denmark)

    Hattel, Jesper Henri

    2008-01-01

    Integrated modelling of entire process sequences and the subsequent in-service conditions, and multiphysics modelling of the single process steps are areas that increasingly support optimisation of manufactured parts. In the present paper, three different examples of modelling manufacturing...... processes from the viewpoint of combined materials and process modelling are presented: solidification of thin walled ductile cast iron, integrated modelling of spray forming and multiphysics modelling of friction stir welding. The fourth example describes integrated modelling applied to a failure analysis...

  7. Homogenous and heterogeneous combustion in the secondary chamber of a straw-fired batch boiler

    Directory of Open Access Journals (Sweden)

    Szubel Mateusz

    2017-01-01

    Full Text Available Currently, the attention of the producers of biomass batch boilers is mostly focused on the problem of the total efficiency of energy conversion, CO emissions as well as particulate matter emissions. Due to the regulations of the European Union, the emissions referred to above have to be kept at certain levels because of health considerations, but also because of the necessity to increase the efficiency of the devices. The paper presents the process of analysis of a straw-fired small-scale boiler. In this study, the early stage CFD model presented in a previous paper [1] has been improved and evaluated. Based on [2], an additional set of specimens participating in homogeneous gas reactions was assumed to describe the combustion process sufficiently. Associated Arrhenius parameters have been applied for the description of these reactions. ANSYS Fluent 16 has been used to perform the analysis and the analysis was focused on the CO emissions level as well as on the impact of the modelling approach on the result of the computing. Moreover, losses related to incomplete combustion have been calculated for each of the considered cases.

  8. CHP Integrated with Burners for Packaged Boilers

    Energy Technology Data Exchange (ETDEWEB)

    Castaldini, Carlo; Darby, Eric

    2013-09-30

    The objective of this project was to engineer, design, fabricate, and field demonstrate a Boiler Burner Energy System Technology (BBEST) that integrates a low-cost, clean burning, gas-fired simple-cycle (unrecuperated) 100 kWe (net) microturbine (SCMT) with a new ultra low-NOx gas-fired burner (ULNB) into one compact Combined Heat and Power (CHP) product that can be retrofit on new and existing industrial and commercial boilers in place of conventional burners. The Scope of Work for this project was segmented into two principal phases: (Phase I) Hardware development, assembly and pre-test and (Phase II) Field installation and demonstration testing. Phase I was divided into five technical tasks (Task 2 to 6). These tasks covered the engineering, design, fabrication, testing and optimization of each key component of the CHP system principally, ULNB, SCMT, assembly BBEST CHP package, and integrated controls. Phase I work culminated with the laboratory testing of the completed BBEST assembly prior to shipment for field installation and demonstration. Phase II consisted of two remaining technical tasks (Task 7 and 8), which focused on the installation, startup, and field verification tests at a pre-selected industrial plant to document performance and attainment of all project objectives. Technical direction and administration was under the management of CMCE, Inc. Altex Technologies Corporation lead the design, assembly and testing of the system. Field demonstration was supported by Leva Energy, the commercialization firm founded by executives at CMCE and Altex. Leva Energy has applied for patent protection on the BBEST process under the trade name of Power Burner and holds the license for the burner currently used in the product. The commercial term Power Burner is used throughout this report to refer to the BBEST technology proposed for this project. The project was co-funded by the California Energy Commission and the Southern California Gas Company (SCG), a

  9. Collapse models and perceptual processes

    International Nuclear Information System (INIS)

    Ghirardi, Gian Carlo; Romano, Raffaele

    2014-01-01

    Theories including a collapse mechanism have been presented various years ago. They are based on a modification of standard quantum mechanics in which nonlinear and stochastic terms are added to the evolution equation. Their principal merits derive from the fact that they are mathematically precise schemes accounting, on the basis of a unique universal dynamical principle, both for the quantum behavior of microscopic systems as well as for the reduction associated to measurement processes and for the classical behavior of macroscopic objects. Since such theories qualify themselves not as new interpretations but as modifications of the standard theory they can be, in principle, tested against quantum mechanics. Recently, various investigations identifying possible crucial test have been discussed. In spite of the extreme difficulty to perform such tests it seems that recent technological developments allow at least to put precise limits on the parameters characterizing the modifications of the evolution equation. Here we will simply mention some of the recent investigations in this direction, while we will mainly concentrate our attention to the way in which collapse theories account for definite perceptual process. The differences between the case of reductions induced by perceptions and those related to measurement procedures by means of standard macroscopic devices will be discussed. On this basis, we suggest a precise experimental test of collapse theories involving conscious observers. We make plausible, by discussing in detail a toy model, that the modified dynamics can give rise to quite small but systematic errors in the visual perceptual process.

  10. Hillslope runoff processes and models

    Science.gov (United States)

    Kirkby, Mike

    1988-07-01

    Hillslope hydrology is concerned with the partition of precipitation as it passes through the vegetation and soil between overland flow and subsurface flow. Flow follows routes which attenuate and delay the flow to different extents, so that a knowledge of the relevant mechanisms is important. In the 1960s and 1970s, hillslope hydrology developed as a distinct topic through the application of new field observations to develop a generation of physically based forecasting models. In its short history, theory has continually been overturned by field observation. Thus the current tendency, particularly among temperate zone hydrologists, to dismiss all Hortonian overland flow as a myth, is now being corrected by a number of significant field studies which reveal the great range in both climatic and hillslope conditions. Some recent models have generally attempted to simplify the processes acting, for example including only vertical unsaturated flow and lateral saturated flows. Others explicitly forecast partial or contributing areas. With hindsight, the most complete and distributed models have generally shown little forecasting advantage over simpler approaches, perhaps trending towards reliable models which can run on desk top microcomputers. The variety now being recognised in hillslope hydrological responses should also lead to models which take account of more complex interactions, even if initially with a less secure physical and mathematical basis than the Richards equation. In particular, there is a need to respond to the variety of climatic responses, and to spatial variability on and beneath the surface, including the role of seepage macropores and pipes which call into question whether the hillside can be treated as a Darcian flow system.

  11. Business Process Modelling for Measuring Quality

    NARCIS (Netherlands)

    Heidari, F.; Loucopoulos, P.; Brazier, F.M.

    2013-01-01

    Business process modelling languages facilitate presentation, communication and analysis of business processes with different stakeholders. This paper proposes an approach that drives specification and measurement of quality requirements and in doing so relies on business process models as

  12. Reduction efficiency prediction of CENIBRA's recovery boiler by direct minimization of gibbs free energy

    Directory of Open Access Journals (Sweden)

    W. L. Silva

    2008-09-01

    Full Text Available The reduction efficiency is an important variable during the black liquor burning process in the Kraft recovery boiler. This variable value is obtained by slow experimental routines and the delay of this measure disturbs the pulp and paper industry customary control. This paper describes an optimization approach for the reduction efficiency determination in the furnace bottom of the recovery boiler based on the minimization of the Gibbs free energy. The industrial data used in this study were directly obtained from CENIBRA's data acquisition system. The resulting approach is able to predict the steady state behavior of the chemical composition of the furnace recovery boiler, - especially the reduction efficiency when different operational conditions are used. This result confirms the potential of this approach in the analysis of the daily operation of the recovery boiler.

  13. Coal-fired boiler houses in Cracow present state and possibilities to improve their efficiency

    Energy Technology Data Exchange (ETDEWEB)

    Cyklis, P. [Institute of Industrial Equipment and Power Engineering, Cracow (Poland); Butcher, T.A. [Brookhaven National Lab., Upton, NY (United States)

    1995-12-31

    A significant amount of heat energy both for heating and process purposes is generated in Cracow, Poland in small-and medium size local boiler houses. The operating procedure of these boiler houses is most often economically and ecologically ineffective because of the bad condition of boilers and lack of funds to install automation, control and measurement equipment. Within the Polish-American Program of Elimination of Low Emission Sources financed by the US Department of Energy, the ENERGOEKSPERT Co., Ltd. investigated chosen boiler houses in Cracow, commissioned by the Cracow Development Office. The results of these investigations were subject of engineering analysis carried out at the Institute of Industrial Equipment and Power Engineering, Technical University, Cracow. The analysis proved that the low-cost improvement of economic efficiency and reduction of air pollutant emission is feasible for combustion of coal fuels.

  14. Numerical investigation on the flow, combustion, and NOX emission characteristics in a 660 MWe tangential firing ultra-supercritical boiler

    Directory of Open Access Journals (Sweden)

    Wenjing Sun

    2016-02-01

    Full Text Available A three-dimensional numerical simulation was carried out to study the pulverized-coal combustion process in a tangentially fired ultra-supercritical boiler. The realizable k-ε model for gas coupled with discrete phase model for coal particles, P-1 radiation model for radiation, two-competing-rates model for devolatilization, and kinetics/diffusion-limited model for combustion process are considered. The characteristics of the flow field, particle motion, temperature distribution, species components, and NOx emissions were numerically investigated. The good agreement of the measurements and predictions implies that the applied simulation models are appropriate for modeling commercial-scale coal boilers. It is found that an ideal turbulent flow and particle trajectory can be observed in this unconventional pulverized-coal furnace. With the application of over-fire air and additional air, lean-oxygen combustion takes place near the burner sets region and higher temperature at furnace exit is acquired for better heat transfer. Within the limits of secondary air, more steady combustion process is achieved as well as the reduction of NOx. Furthermore, the influences of the secondary air, over-fire air, and additional air on the NOx emissions are obtained. The numerical results reveal that NOx formation attenuates with the decrease in the secondary air ratio (γ2nd and the ratio of the additional air to the over-fire air (γAA/γOFA was within the limits.

  15. 46 CFR 61.05-15 - Boiler mountings and attachments.

    Science.gov (United States)

    2010-10-01

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

  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. Synchrotron and Coulomb Boiler in Cygnus X-1

    International Nuclear Information System (INIS)

    Malzac, Julien; Belmont, Renaud

    2009-01-01

    We use a new code to simulate the radiation and kinetic processes in the X-ray emitting region around accreting black holes and constrain the magnetic field and temperature of the hot protons in the corona of Cygnus X-1. In the hard state we find a magnetic field below equipartition with radiation, suggesting that the corona is not powered through magnetic field dissipation (as assumed in most accretion disc corona models). On the other hand, our results also point toward proton temperatures that are substantially lower than typical temperatures of the ADAF models. Finally, we show that in both spectral states Comptonising plasma could be powered essentially through power-law acceleration of non-thermal electrons, which are then partly thermalised by the synchrotron and Coulomb boiler. This suggests that, contrary to current beliefs, the corona of the HSS and that of the LHS could be of very similar nature. The differences between the LHS and HSS coronal spectra would then be predominantly caused by the strong disc soft cooling emission which is present in the HSS and absent in the LHS.

  19. Thermal Efficiency of Power Module “Boiler with Solar Collectors as Additional Heat Source” For Combined Heat Supply System

    Directory of Open Access Journals (Sweden)

    Denysova A.E.

    2015-04-01

    Full Text Available The purpose of work is to increase the efficiency of the combined heat supply system with solar collectors as additional thermal generators. In order to optimize the parameters of combined heat supply system the mathematical modeling of thermal processes in multi module solar collectors as additional thermal generators for preheating of the water for boiler have been done. The method of calculation of multi-module solar collectors working with forced circulation for various configurations of hydraulic connection of solar collector modules as the new result of our work have been proposed. The results of numerical simulation of thermal efficiency of solar heat source for boiler of combined heat supply system with the account of design features of the circuit; regime parameters of thermal generators that allow establishing rational conditions of its functioning have been worked out. The conditions of functioning that provide required temperature of heat carrier incoming to boiler and value of flow rate at which the slippage of heat carrier is not possible for different hydraulic circuits of solar modules have been established.

  20. Advanced, Low/Zero Emission Boiler Design and Operation

    Energy Technology Data Exchange (ETDEWEB)

    Babcock/Wilcox; Illinois State Geological; Worley Parsons; Parsons Infrastructure/Technology Group

    2007-06-30

    In partnership with the U.S. Department of Energy's National Energy Technology Laboratory, B&W and Air Liquide are developing and optimizing the oxy-combustion process for retrofitting existing boilers as well as new plants. The main objectives of the project is to: (1) demonstrate the feasibility of the oxy-combustion technology with flue gas recycle in a 5-million Btu/hr coal-fired pilot boiler, (2) measure its performances in terms of emissions and boiler efficiency while selecting the right oxygen injection and flue gas recycle strategies, and (3) perform technical and economic feasibility studies for application of the technology in demonstration and commercial scale boilers. This document summarizes the work performed during the period of performance of the project (Oct 2002 to June 2007). Detailed technical results are reported in corresponding topical reports that are attached as an appendix to this report. Task 1 (Site Preparation) has been completed in 2003. The experimental pilot-scale O{sub 2}/CO{sub 2} combustion tests of Task 2 (experimental test performance) has been completed in Q2 2004. Process simulation and cost assessment of Task 3 (Techno-Economic Study) has been completed in Q1 2005. The topical report on Task 3 has been finalized and submitted to DOE in Q3 2005. The calculations of Task 4 (Retrofit Recommendation and Preliminary Design of a New Generation Boiler) has been completed in 2004. In Task 6 (engineering study on retrofit applications), the engineering study on 25MW{sub e} unit has been completed in Q2, 2008 along with the corresponding cost assessment. In Task 7 (evaluation of new oxy-fuel power plants concepts), based on the design basis document prepared in 2005, the design and cost estimate of the Air Separation Units, the boiler islands and the CO{sub 2} compression and trains have been completed, for both super and ultra-supercritical case study. Final report of Task-7 is published by DOE in Oct 2007.

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

    International Nuclear Information System (INIS)

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

    1984-01-01

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

  2. 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

  3. 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

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-12-15

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

  6. Biomass boiler energy conversion system analysis with the aid of exergy-based methods

    International Nuclear Information System (INIS)

    Li, Changchun; Gillum, Craig; Toupin, Kevin; Donaldson, Burl

    2015-01-01

    Highlights: • Conventional exergy analysis and advanced exergy analysis are performed. • The combustion process dominates the exergy destruction. • Increase excess air will decrease the overall boiler exergy efficiency. • Increase the SH temperatures will increase the overall boiler exergy efficiency. • The avoidable exergy destructions in the air heaters are very small. - Abstract: The objective of this paper is to establish a theoretical framework for the exergy analysis and advanced exergy analysis of a real biomass boiler. These analyses can be used for both the diagnosis and optimization of a biomass boiler as well as for the design of a new biomass boiler. Conventional exergy analysis is performed to recognize the source(s) of inefficiency and irreversibility and identify exergy destruction in different components of the biomass boiler. An advanced exergy analysis is performed to provide comprehensive information about the avoidable exergy destruction and real fuel-saving potential for each component, as well as the overall system. Sensitivity studies of several design parameters including the excess air, biomass moisture and steam parameters were evaluated. The results show that the maximum exergy destruction occurs in the combustion process, followed by the Water Walls (WW) & Radiant Superheater (RSH) and the Low Temperature Superheater (LTSH). The fuel-saving and exergy efficiency improvement strategies for different components are discussed in this paper

  7. 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)

  8. Boiler feedwater treatment using reverse osmosis at Suncor OSG

    International Nuclear Information System (INIS)

    Brown, T.

    1997-01-01

    The installation of a new 1000 cu m/hr reverse osmosis water treatment system for boiler feedwater at a Suncor plant was discussed. The selection process began in 1993 when Suncor identified a need to increase its boiler feedwater capacity. The company reviewed many options available to increase the treated water capacity. These included: contracting the supply of treated water, adding additional capacity, replacing the entire plant, reverse osmosis, and demineralization. The eventual decision was to build a new 1000 cu m/hr reverse osmosis water treatment plant with the following key components: a Degremont Infilco Ultra Pulsator Clarifier and a Glegg Water Conditioning multimedia filter, Amberpack softeners and reverse osmosis arrays. The reverse osmosis plant was environmentally favourable over an equivalent demineralization plant. A technical comparison was provided between demineralization and reverse osmosis. The system has proven to be successful and economical in meeting the plants needs. 5 figs

  9. Thermal Effects by Firing Oil Shale Fuel in CFB Boilers

    Science.gov (United States)

    Neshumayev, D.; Ots, A.; Parve, T.; Pihu, T.; Plamus, K.; Prikk, A.

    It is well known that during firing of oil shale fuel the amount of heat released during its combustion per kg of fuel is significantly affected by the endothermic and exothermic processes taking place in mineral matter. These thermal effects are calcite and dolomite decomposing, marcasite FeS2 oxidising, CaO sulphation and formation of the new minerals. The given paper deals with the experimental study of the influence of these thermal effects of oil shale fuel having different heating value on total amount of heat released during combustion in calorimetric bomb, circulating fluidized bed (CFB) and pulverized-firing boiler (PFB). The large-scale (250 MWth) experiments were performed in the K11-1 CFB boiler of the Balti Power Plant. During experiments low heating value of a fuel varied within the range 8.5-11 MJ/kg. At the end some conclusions were drawn.

  10. Properties of spatial Cox process models

    DEFF Research Database (Denmark)

    Møller, Jesper

    Probabilistic properties of Cox processes of relevance for statistical modelling and inference are studied. Particularly, we study the most important classes of Cox processes, including log Gaussian Cox processes, shot noise Cox processes, and permanent Cox processes. We consider moment properties...... and point process operations such as thinning, displacements, and superpositioning. We also discuss how to simulate specific Cox processes....

  11. Developing engineering processes through integrated modelling of product and process

    DEFF Research Database (Denmark)

    Nielsen, Jeppe Bjerrum; Hvam, Lars

    2012-01-01

    This article aims at developing an operational tool for integrated modelling of product assortments and engineering processes in companies making customer specific products. Integrating a product model in the design of engineering processes will provide a deeper understanding of the engineering...... activities as well as insight into how product features affect the engineering processes. The article suggests possible ways of integrating models of products with models of engineering processes. The models have been tested and further developed in an action research study carried out in collaboration...... with a major international engineering company....

  12. Automatic extraction of process categories from process model collections

    NARCIS (Netherlands)

    Malinova, M.; Dijkman, R.M.; Mendling, J.; Lohmann, N.; Song, M.; Wohed, P.

    2014-01-01

    Many organizations build up their business process management activities in an incremental way. As a result, there is no overarching structure defined at the beginning. However, as business process modeling initiatives often yield hundreds to thousands of process models, there is a growing need for

  13. 40 CFR 63.496 - Back-end process provisions-procedures to determine compliance using control or recovery devices.

    Science.gov (United States)

    2010-07-01

    ... boiler or process heater. (iii) The control efficiency of the boiler or process heater shall be calculated using Equation 29. ER05SE96.027 where: R=Control efficiency of boiler or process heater, percent..., the control efficiency of the boiler or process heater shall be determined using the procedures in...

  14. Specific Emissions of Harmful Substances from Small Boilers

    Directory of Open Access Journals (Sweden)

    Horák Jiøí

    1998-09-01

    Full Text Available Coal is on of the most important energy source and its significance will increase in a future. In Czech republic coal is except else widely used as a fuel for combustion in a small boilers (up to 50 kW. Low efficiency of the small boilers which is often below 50% together with high emissions of the harmful substances into near surroundings cause in average 40 – 70% of total local air pollution. The research was performed in a scope of the Grant no. 101/98/0820 of Grant Agency of Czech Republic was focused on quality of combustion process related to combustion efficiency and creation of harmful substances at combustion of domestic fuels. Experiments were performed to compare combustion of brown coal, clack coal, coke and black coal slurry. Extremely high creation of harmful substances (CO, NOX, solid particles and organic substances was measured when the black coal slurry was used as a fuel, measured in kg of emissions per GJ of burned fuel. Combustion of brown coal produced significant emissions of solid particles which bond harmful substances as metals, polyaromatic hydrocarbons and others together with high emissions of SO2 . Strong dependence between emissions of CO and low quality of combustion given by low combustion temperature, shortage of combustion air, not suitable design of after-combustion chamber and short duration of fuel presence in a combustion area was found out. Emissions of wide range of metals were investigated. The results of the research grant project describe and explain the combustion process and creation of harmful substances in small boilers plus give suggestions and recommendations leading to rational operation of the small boilers and lowering their negative impact to environment.

  15. Imulation of temperature field in swirl pulverized coal boiler

    Science.gov (United States)

    Lv, Wei; Wu, Weifeng; Chen, Chen; Chen, Weifeng; Qi, Guoli; Zhang, Songsong

    2018-02-01

    In order to achieve the goal of energy saving and emission reduction and energy efficient utilization, taking a 58MW swirl pulverized coal boiler as the research object, the three-dimensional model of the rotor is established. According to the principle of CFD, basic assumptions and boundary conditions are selected, the temperature field in the furnace of 6 kinds of working conditions is numerically solved, and the temperature distribution in the furnace is analyzed. The calculation results show that the temperature of the working condition 1 is in good agreement with the experimental data, and the error is less than 10%,the results provide a theoretical basis for the following calculation. Through the comparison of the results of the 6 conditions, it is found that the working condition 3 is the best operating condition of the pulverized coal boiler.

  16. Multi-pressure boiler thermodynamics analysis code

    International Nuclear Information System (INIS)

    Lorenzoni, G.

    1992-01-01

    A new method and the relative FORTRAN program for the thermodynamics design analysis of a multipressure boiler are reported. This method permits the thermodynamics design optimization with regard to total exergy production and a preliminary costs

  17. Pirotubular boilers design. Diseno de calderas pirotubulares

    Energy Technology Data Exchange (ETDEWEB)

    Latre Durso, F. (Geval S.A. (Spain))

    1994-01-01

    This article describes the conceptual design of Pirotubular boilers from the valuable thermal point of view, to the dimensional. This topic is a very tool valuable for professionals of design and for maintenance and operation equipment.

  18. 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

  19. Catalytic burners in larger boiler appliances

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-02-15

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

  20. Analysis of proposed eco-design requirements for boilers and water heaters. Paper within the framwork of the ''Material Efficiency and Resource Conservation'' (MaRess) Project - Task 14

    Energy Technology Data Exchange (ETDEWEB)

    Barthel, Klaus; Franke, Moritz [Wuppertal Institute for Climate, Environment and Energy, Wuppertal (Germany)

    2009-12-15

    -temperature boilers by the ban in 2013 amounts to approx. 25 % (152,000 units) of Germany's heating market today. In addition, condensing boilers would be banned to some extent. Besides changes in market shares, several financial support programmes will have to be adjusted in Germany including inter alia the programmes ''Energieeffizient Bauen'', ''Energieeffizient Sanieren'' and the ''Marktanreizprogramm'' for renewable energies. Furthermore, the ''1. BImSchV'' in Germany will need to be revised, e.g. in the context of NOx limits. A comprehensive approach has been chosen within Lot 1/2 taking into account the whole heating system (hybrids or stand-alones with/without solar and/or heat pumps), including e.g. heating system components like the control chain. This concept is called ''system approach'' or better ''enlarged product approach''. It is in contrast to heating product approaches in other lots of the ecodesign directive process. There are arguments for and against the enlarged product approach. Advantages include e.g. the achievement of larger energy savings in comparison to component approach. One major disadvantage is the practical implementation which remains questionable. In the beginning of June 2009, the European Commission has distributed a revised WD for possible measures on ecodesign and energy labelling for boilers. A new version of the Ecoboiler model has also been provided in addition to the WD (cf. chapter 10). Many changes have been made concerning both the WD and the Ecoboiler model. On the one hand, the Ecoboiler model has been simplified. However, due to missing input data needed for the new model calculation, but not yet available from the manufacturers, these latest version of the Ecoboiler model could not be analysed comprehensively. Nevertheless, Wuppertal Institute assumes that results in general will be comparable to calculations

  1. Process mining using BPMN: relating event logs and process models

    NARCIS (Netherlands)

    Kalenkova, A.A.; van der Aalst, W.M.P.; Lomazova, I.A.; Rubin, V.A.

    2017-01-01

    Process-aware information systems (PAIS) are systems relying on processes, which involve human and software resources to achieve concrete goals. There is a need to develop approaches for modeling, analysis, improvement and monitoring processes within PAIS. These approaches include process mining

  2. Process mining using BPMN : relating event logs and process models

    NARCIS (Netherlands)

    Kalenkova, A.A.; Aalst, van der W.M.P.; Lomazova, I.A.; Rubin, V.A.

    2015-01-01

    Process-aware information systems (PAIS) are systems relying on processes, which involve human and software resources to achieve concrete goals. There is a need to develop approaches for modeling, analysis, improvement and monitoring processes within PAIS. These approaches include process mining

  3. Development and test of small-scale batch-fired straw boilers in Denmark

    International Nuclear Information System (INIS)

    Kristensen, E.F.; Kristensen, J.K.

    2004-01-01

    In Denmark, government subsidies for the testing and installation of biomass-fired boilers were available for the period from 1995 until 2002. Each boiler type had to pass an official approval test to achieve subsidy. The combustion abilities of the boiler were optimized prior to the test. The main aim of this subsidy was to encourage the development of energy-efficient and environmentally friendly boilers. The scheme was therefore organized in such a way that the greatest subsidies were awarded for boilers with high efficiency and low emissions. This goal has in effect been achieved for batch-fired straw boilers, where the typical efficiency has been increased from about 75% in 1995 to about 87% in 2002. Similarly, the carbon monoxide emissions have been reduced from 5000 ppm (reference value 10% O 2 ) in 1995 to less than 1000 ppm in 2002. These improvements are mainly due to better insulation inside the combustion chamber, more efficient techniques for supplying air to the combustion process, improved cooling of the flue gas, and optimization of the electronic control unit for the air supply

  4. 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

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

  6. Boiler burden reduced at Bedford site.

    Science.gov (United States)

    Horsley, Chris

    2011-10-01

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

  7. 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

  8. Gas fired boilers and atmospheric pollution

    International Nuclear Information System (INIS)

    Chiaranello, J.M.

    1991-01-01

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

  9. Multiphysics modelling of manufacturing processes: A review

    DEFF Research Database (Denmark)

    Jabbari, Masoud; Baran, Ismet; Mohanty, Sankhya

    2018-01-01

    Numerical modelling is increasingly supporting the analysis and optimization of manufacturing processes in the production industry. Even if being mostly applied to multistep processes, single process steps may be so complex by nature that the needed models to describe them must include multiphysics...... the diversity in the field of modelling of manufacturing processes as regards process, materials, generic disciplines as well as length scales: (1) modelling of tape casting for thin ceramic layers, (2) modelling the flow of polymers in extrusion, (3) modelling the deformation process of flexible stamps...... for nanoimprint lithography, (4) modelling manufacturing of composite parts and (5) modelling the selective laser melting process. For all five examples, the emphasis is on modelling results as well as describing the models in brief mathematical details. Alongside with relevant references to the original work...

  10. Modeling Suspension and Continuation of a Process

    Directory of Open Access Journals (Sweden)

    Oleg Svatos

    2012-04-01

    Full Text Available This work focuses on difficulties an analyst encounters when modeling suspension and continuation of a process in contemporary process modeling languages. As a basis there is introduced general lifecycle of an activity which is then compared to activity lifecycles supported by individual process modeling languages. The comparison shows that the contemporary process modeling languages cover the defined general lifecycle of an activity only partially. There are picked two popular process modeling languages and there is modeled real example, which reviews how the modeling languages can get along with their lack of native support of suspension and continuation of an activity. Upon the unsatisfying results of the contemporary process modeling languages in the modeled example, there is presented a new process modeling language which, as demonstrated, is capable of capturing suspension and continuation of an activity in much simpler and precise way.

  11. Computer Aided Continuous Time Stochastic Process Modelling

    DEFF Research Database (Denmark)

    Kristensen, N.R.; Madsen, Henrik; Jørgensen, Sten Bay

    2001-01-01

    A grey-box approach to process modelling that combines deterministic and stochastic modelling is advocated for identification of models for model-based control of batch and semi-batch processes. A computer-aided tool designed for supporting decision-making within the corresponding modelling cycle...

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

    Science.gov (United States)

    Peantong, Sasitorn; Tangjitsitcharoen, Somkiat

    2017-06-01

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

  13. Process modeling for Humanities: tracing and analyzing scientific processes

    OpenAIRE

    Hug , Charlotte; Salinesi , Camille; Deneckere , Rebecca; Lamasse , Stéphane

    2011-01-01

    International audience; This paper concerns epistemology and the understanding of research processes in Humanities, such as Archaeology. We believe that to properly understand research processes, it is essential to trace them. The collected traces depend on the process model established, which has to be as accurate as possible to exhaustively record the traces. In this paper, we briefly explain why the existing process models for Humanities are not sufficient to represent traces. We then pres...

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

    Science.gov (United States)

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

    2017-02-07

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

  15. Optimization of a Centrifugal Boiler Circulating Pump's Casing Based on CFD and FEM Analyses

    Directory of Open Access Journals (Sweden)

    Zhigang Zuo

    2014-04-01

    Full Text Available It is important to evaluate the economic efficiency of boiler circulating pumps in manufacturing process from the manufacturers' point of view. The possibility of optimizing the pump casing with respect to structural pressure integrity and hydraulic performance was discussed. CFD analyses of pump models with different pump casing sizes were firstly carried out for the hydraulic performance evaluation. The effects of the working temperature and the sealing ring on the hydraulic efficiency were discussed. A model with casing diameter of 0.875D40 was selected for further analyses. FEM analyses were then carried out on different combinations of casing sizes, casing wall thickness, and materials, to evaluate its safety related to pressure integrity, with respect to both static and fatigue strength analyses. Two models with forging and cast materials were selected as final results.

  16. Business process modeling for processing classified documents using RFID technology

    Directory of Open Access Journals (Sweden)

    Koszela Jarosław

    2016-01-01

    Full Text Available The article outlines the application of the processing approach to the functional description of the designed IT system supporting the operations of the secret office, which processes classified documents. The article describes the application of the method of incremental modeling of business processes according to the BPMN model to the description of the processes currently implemented (“as is” in a manual manner and target processes (“to be”, using the RFID technology for the purpose of their automation. Additionally, the examples of applying the method of structural and dynamic analysis of the processes (process simulation to verify their correctness and efficiency were presented. The extension of the process analysis method is a possibility of applying the warehouse of processes and process mining methods.

  17. Process correlation analysis model for process improvement identification.

    Science.gov (United States)

    Choi, Su-jin; Kim, Dae-Kyoo; Park, Sooyong

    2014-01-01

    Software process improvement aims at improving the development process of software systems. It is initiated by process assessment identifying strengths and weaknesses and based on the findings, improvement plans are developed. In general, a process reference model (e.g., CMMI) is used throughout the process of software process improvement as the base. CMMI defines a set of process areas involved in software development and what to be carried out in process areas in terms of goals and practices. Process areas and their elements (goals and practices) are often correlated due to the iterative nature of software development process. However, in the current practice, correlations of process elements are often overlooked in the development of an improvement plan, which diminishes the efficiency of the plan. This is mainly attributed to significant efforts and the lack of required expertise. In this paper, we present a process correlation analysis model that helps identify correlations of process elements from the results of process assessment. This model is defined based on CMMI and empirical data of improvement practices. We evaluate the model using industrial data.

  18. Syntax highlighting in business process models

    NARCIS (Netherlands)

    Reijers, H.A.; Freytag, T.; Mendling, J.; Eckleder, A.

    2011-01-01

    Sense-making of process models is an important task in various phases of business process management initiatives. Despite this, there is currently hardly any support in business process modeling tools to adequately support model comprehension. In this paper we adapt the concept of syntax

  19. Configurable multi-perspective business process models

    NARCIS (Netherlands)

    La Rosa, M.; Dumas, M.; Hofstede, ter A.H.M.; Mendling, J.

    2011-01-01

    A configurable process model provides a consolidated view of a family of business processes. It promotes the reuse of proven practices by providing analysts with a generic modeling artifact from which to derive individual process models. Unfortunately, the scope of existing notations for

  20. Sulphur recirculation for reduced boiler corrosion; Minskad pannkorrosion med svavelrecirkulation

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Sven; Karlsson, Martin (Goetaverken Miljoe AB, Goeteborg (Sweden)); Blomqvist, Evalena; Baefver, Linda; Claesson, Frida; Davidsson, Kent (SP Sveriges Tekniska Forskningsinstitut, Boraas (Sweden)); Froitzheim, Jan; Pettersson, Jesper; Steenari, Britt-Marie (Chalmers Tekniska Hoegskola, Oorganisk miljoekemi, Goeteborg (Sweden))

    2010-03-15

    Sulphur recirculation is a new technology for reducing boiler corrosion and dioxin formation, which was demonstrated in full-scale tests performed at the Renova Waste to Energy plant at Saevenaes in Goeteborg (Sweden). Sulphur is recirculated from the flue gas cleaning back to the boiler, which reduces the chloride content of the deposits, which in turn reduces boiler corrosion and dioxin formation. Sulphur dioxide was separated from the flue gas in a wet scrubber by adding hydrogen peroxide, producing sulphuric acid. The sulphuric acid was injected into the furnace using nozzles with atomization air, surrounded by recirculated flue gas for improved mixing. By recirculating the sulphur, the sulphur dioxide concentration was increased in the boiler. Each sulphur atom passed the boiler several times and no external sulphur had to be added. Dioxin, ash, deposits and particle samplings together with 1000 h corrosion probe measurements were performed for normal operation (reference) and with sulphur recirculation respectively. During spring 2009, reference measurements were made and the recirculation system was installed and tested. During autumn 2009, a long term test with sulphur recirculation was made. An SO{sub 2} concentration of approximately 800 mg/m3 (n, d.g.) was maintained in the boiler by the system except during a period of extremely low sulphur content in the waste. The sulphur dioxide stack concentrations have been far below the emission limit. Sulphuric acid dew point measurements have shown that the sulphuric acid dosage did not lead to elevated SO{sub 3} concentrations, which may otherwise lead to low temperature corrosion. The chlorine content of both fly ash and boiler ash decreased and the sulphur content increased during the sulphur recirculation tests. The molar chlorine/sulphur ratio (Cl/S) decreased by two thirds in the fly ash as well as in the boiler ash, except for one sample. With sulphur recirculation in operation, the deposit growth was

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

    International Nuclear Information System (INIS)

    Chong, W.C.; Rashid, M.; Ramli, M.; Zainura, Z.N.; NorRuwaida, J.

    2010-01-01

    A study to investigate the particulate emission from a boiler of a palm oil mill plant equipped with a multi-cyclones particulate arrest or was performed and reported in this paper. The particulate emission concentration was measured at the outlet of a 8 mt/ hr capacity water-tube typed boiler of a palm oil mill plant processing 27mt/ hr of fresh fruit bunch (FFB). The particulate sample was collected iso-kinetically using the USEPA method 5 sampling train through a sampling port made at the duct of the exiting flue gas between the boiler and a multi-cyclones unit. Results showed that the particulate emission rates exiting the boiler varied from 0.09 to 0.60 g/s with an average of 0.29 + 0.18 g/ s. While the average particulate emission concentration exiting the boiler was 12.1 + 7.36 g/ Nm 3 (corrected to 7 % oxygen concentration), ranging from 3.62 to 25.3 g/ Nm 3 (at 7 % O 2 ) of the flue gas during the measurement. Based on the 27 mt/ hr FFB processed and the capacity of the boiler of 8mt steam/ hr, the calculated particulate emission factor was 39 g particulate/ mt FFB processed or 131 g particulate/ mt boiler capacity, respectively. In addition, based on the finding and in order to comply with the emission limits of 0.4 g/ Nm 3 , the collection efficiency of any given particulate emission pollution control system to consider for the mill will be from 87 to 98 %, which is not easily achievable with the existing multi-cyclones unit. A considerable amount of efforts are still needed pertaining to the particulate emission control problem in the industry. (author)

  2. Pelly Crossing wood chip boiler

    Energy Technology Data Exchange (ETDEWEB)

    1985-03-11

    The Pelly wood chip project has demonstrated that wood chips are a successful fuel for space and domestic water heating in a northern climate. Pelly Crossing was chosen as a demonstration site for the following reasons: its extreme temperatures, an abundant local supply of resource material, the high cost of fuel oil heating and a lack of local employment. The major obstacle to the smooth operation of the boiler system was the poor quality of the chip supply. The production of poor quality chips has been caused by inadequate operation and maintenance of the chipper. Dull knives and faulty anvil adjustments produced chips and splinters far in excess of the one centimetre size specified for the system's design. Unanticipated complications have caused costs of the system to be higher than expected by approximately $15,000. The actual cost of the project was approximately $165,000. The first year of the system's operation was expected to accrue $11,600 in heating cost savings. This estimate was impossible to confirm given the system's irregular operation and incremental costs. Consistent operation of the system for a period of at least one year plus the installation of monitoring devices will allow the cost effectiveness to be calculated. The wood chip system's impact on the environment was estimated to be minimal. Wood chip burning was considered cleaner and safer than cordwood burning. 9 refs., 6 figs., 6 tabs.

  3. 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)

  4. User's manual for a process model code

    International Nuclear Information System (INIS)

    Kern, E.A.; Martinez, D.P.

    1981-03-01

    The MODEL code has been developed for computer modeling of materials processing facilities associated with the nuclear fuel cycle. However, it can also be used in other modeling applications. This report provides sufficient information for a potential user to apply the code to specific process modeling problems. Several examples that demonstrate most of the capabilities of the code are provided

  5. Repairing process models to reflect reality

    NARCIS (Netherlands)

    Fahland, D.; Aalst, van der W.M.P.; Barros, A.; Gal, A.; Kindler, E.

    2012-01-01

    Process mining techniques relate observed behavior (i.e., event logs) to modeled behavior (e.g., a BPMN model or a Petri net). Processes models can be discovered from event logs and conformance checking techniques can be used to detect and diagnose differences between observed and modeled behavior.

  6. ASSESSMENT OF CONTROL TECHNOLOGIES FOR REDUCING EMISSIONS OF SO2 AND NOX FROM EXISTING COAL-FIRED UTILITY BOILERS

    Science.gov (United States)

    The report reviews information and estimated costs on 15 emissioncontrol technology categories applicable to existing coal-fired electric utility boilers. he categories include passive controls such as least emission dispatching, conventional processes, and emerging technologies ...

  7. Genetic Process Mining: Alignment-based Process Model Mutation

    NARCIS (Netherlands)

    Eck, van M.L.; Buijs, J.C.A.M.; Dongen, van B.F.; Fournier, F.; Mendling, J.

    2015-01-01

    The Evolutionary Tree Miner (ETM) is a genetic process discovery algorithm that enables the user to guide the discovery process based on preferences with respect to four process model quality dimensions: replay fitness, precision, generalization and simplicity. Traditionally, the ETM algorithm uses

  8. 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

  9. Composing Models of Geographic Physical Processes

    Science.gov (United States)

    Hofer, Barbara; Frank, Andrew U.

    Processes are central for geographic information science; yet geographic information systems (GIS) lack capabilities to represent process related information. A prerequisite to including processes in GIS software is a general method to describe geographic processes independently of application disciplines. This paper presents such a method, namely a process description language. The vocabulary of the process description language is derived formally from mathematical models. Physical processes in geography can be described in two equivalent languages: partial differential equations or partial difference equations, where the latter can be shown graphically and used as a method for application specialists to enter their process models. The vocabulary of the process description language comprises components for describing the general behavior of prototypical geographic physical processes. These process components can be composed by basic models of geographic physical processes, which is shown by means of an example.

  10. MORTALITY MODELING WITH LEVY PROCESSES

    Directory of Open Access Journals (Sweden)

    M. Serhat Yucel, FRM

    2012-07-01

    Full Text Available Mortality and longevity risk is usually one of the main risk components ineconomic capital models of insurance companies. Above all, future mortalityexpectations are an important input in the modeling and pricing of long termproducts. Deviations from the expectation can lead insurance company even todefault if sufficient reserves and capital is not held. Thus, Modeling of mortalitytime series accurately is a vital concern for the insurance industry. The aim of thisstudy is to perform distributional and spectral testing to the mortality data andpracticed discrete and continuous time modeling. We believe, the results and thetechniques used in this study will provide a basis for Value at Risk formula incase of mortality.

  11. Model-based software process improvement

    Science.gov (United States)

    Zettervall, Brenda T.

    1994-01-01

    The activities of a field test site for the Software Engineering Institute's software process definition project are discussed. Products tested included the improvement model itself, descriptive modeling techniques, the CMM level 2 framework document, and the use of process definition guidelines and templates. The software process improvement model represents a five stage cyclic approach for organizational process improvement. The cycles consist of the initiating, diagnosing, establishing, acting, and leveraging phases.

  12. Kopernik : modeling business processes for digital customers

    OpenAIRE

    Estañol Lamarca, Montserrat; Castro, Manuel; Díaz-Montenegro, Sylvia; Teniente López, Ernest

    2016-01-01

    This paper presents the Kopernik methodology for modeling business processes for digital customers. These processes require a high degree of flexibility in the execution of their tasks or actions. We achieve this by using the artifact-centric approach to process modeling and the use of condition-action rules. The processes modeled following Kopernik can then be implemented in an existing commercial tool, Balandra.

  13. The triconnected abstraction of process models

    OpenAIRE

    Polyvyanyy, Artem; Smirnov, Sergey; Weske, Mathias

    2009-01-01

    Contents: Artem Polyvanny, Sergey Smirnow, and Mathias Weske The Triconnected Abstraction of Process Models 1 Introduction 2 Business Process Model Abstraction 3 Preliminaries 4 Triconnected Decomposition 4.1 Basic Approach for Process Component Discovery 4.2 SPQR-Tree Decomposition 4.3 SPQR-Tree Fragments in the Context of Process Models 5 Triconnected Abstraction 5.1 Abstraction Rules 5.2 Abstraction Algorithm 6 Related Work and Conclusions

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-03-15

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

  15. Modelling of Batch Process Operations

    DEFF Research Database (Denmark)

    Abdul Samad, Noor Asma Fazli; Cameron, Ian; Gani, Rafiqul

    2011-01-01

    Here a batch cooling crystalliser is modelled and simulated as is a batch distillation system. In the batch crystalliser four operational modes of the crystalliser are considered, namely: initial cooling, nucleation, crystal growth and product removal. A model generation procedure is shown that s...

  16. Mathematical Modeling: A Structured Process

    Science.gov (United States)

    Anhalt, Cynthia Oropesa; Cortez, Ricardo

    2015-01-01

    Mathematical modeling, in which students use mathematics to explain or interpret physical, social, or scientific phenomena, is an essential component of the high school curriculum. The Common Core State Standards for Mathematics (CCSSM) classify modeling as a K-12 standard for mathematical practice and as a conceptual category for high school…

  17. Birth/death process model

    Science.gov (United States)

    Solloway, C. B.; Wakeland, W.

    1976-01-01

    First-order Markov model developed on digital computer for population with specific characteristics. System is user interactive, self-documenting, and does not require user to have complete understanding of underlying model details. Contains thorough error-checking algorithms on input and default capabilities.

  18. Transforming Collaborative Process Models into Interface Process Models by Applying an MDA Approach

    Science.gov (United States)

    Lazarte, Ivanna M.; Chiotti, Omar; Villarreal, Pablo D.

    Collaborative business models among enterprises require defining collaborative business processes. Enterprises implement B2B collaborations to execute these processes. In B2B collaborations the integration and interoperability of processes and systems of the enterprises are required to support the execution of collaborative processes. From a collaborative process model, which describes the global view of the enterprise interactions, each enterprise must define the interface process that represents the role it performs in the collaborative process in order to implement the process in a Business Process Management System. Hence, in this work we propose a method for the automatic generation of the interface process model of each enterprise from a collaborative process model. This method is based on a Model-Driven Architecture to transform collaborative process models into interface process models. By applying this method, interface processes are guaranteed to be interoperable and defined according to a collaborative process.

  19. Orion Boiler Plate Airdrop Test System

    Science.gov (United States)

    Machin, Ricardo A.; Evans, Carol T.

    2013-01-01

    On the 29th of February 2012 the Orion Capsule Parachute Assembly System (CPAS) project attempted to perform an airdrop test of a boilerplate test article for the second time. The first attempt (Cluster Development Test 2, July 2008) to deliver a similar boilerplate from a C-17 using the Low Velocity Air Drop (LVAD) technique resulted in the programmer parachute failing to properly inflate, the test article failing to achieve the desired test initiation conditions, and the test article a total loss. This paper will pick up where the CDT-2 failure investigation left off, describing the test technique that was adopted, and outline the modeling that was performed to gain confidence that the second attempt would be successful. The second boiler plate test (Cluster Development Test 3-3) was indeed a complete success and has subsequently been repeated several times, allowing the CPAS project to proceed with the full scale system level development testing required to integrate the hardware to the first Entry Flight Test vehicle as well as go into the Critical Design Review with minimum risk and a mature design.

  20. Modeling business processes: theoretical and practical aspects

    Directory of Open Access Journals (Sweden)

    V.V. Dubininа

    2015-06-01

    Full Text Available The essence of process-oriented enterprise management has been examined in the article. The content and types of information technology have been analyzed in the article, due to the complexity and differentiation of existing methods, as well as the specificity of language, terminology of the enterprise business processes modeling. The theoretical aspects of business processes modeling have been reviewed and the modern traditional modeling techniques received practical application in the visualization model of retailers activity have been studied in the article. In the process of theoretical analysis of the modeling methods found that UFO-toolkit method that has been developed by Ukrainian scientists due to it systemology integrated opportunities, is the most suitable for structural and object analysis of retailers business processes. It was designed visualized simulation model of the business process "sales" as is" of retailers using a combination UFO-elements with the aim of the further practical formalization and optimization of a given business process.

  1. 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

  2. Ultrasonic boiler inspection and economic analysis guidelines

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

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

  3. A Comparative of business process modelling techniques

    Science.gov (United States)

    Tangkawarow, I. R. H. T.; Waworuntu, J.

    2016-04-01

    In this era, there is a lot of business process modeling techniques. This article is the research about differences of business process modeling techniques. For each technique will explain about the definition and the structure. This paper presents a comparative analysis of some popular business process modelling techniques. The comparative framework is based on 2 criteria: notation and how it works when implemented in Somerleyton Animal Park. Each technique will end with the advantages and disadvantages. The final conclusion will give recommend of business process modeling techniques that easy to use and serve the basis for evaluating further modelling techniques.

  4. Information-Processing Models and Curriculum Design

    Science.gov (United States)

    Calfee, Robert C.

    1970-01-01

    "This paper consists of three sections--(a) the relation of theoretical analyses of learning to curriculum design, (b) the role of information-processing models in analyses of learning processes, and (c) selected examples of the application of information-processing models to curriculum design problems." (Author)

  5. How visual cognition influences process model comprehension

    NARCIS (Netherlands)

    Petrusel, Razvan; Mendling, Jan; Reijers, Hajo A.

    2017-01-01

    Process analysts and other professionals extensively use process models to analyze business processes and identify performance improvement opportunities. Therefore, it is important that such models can be easily and properly understood. Previous research has mainly focused on two types of factors

  6. Social software for business process modeling

    NARCIS (Netherlands)

    Koschmider, A.; Song, M.S.; Reijers, H.A.

    2010-01-01

    Formal models of business processes are used for a variety of purposes. But where the elicitation of the characteristics of a business process usually takes place in a collaborative fashion, the building of the final, formal process model is done mostly by a single person. This article presents the

  7. Measuring similarity between business process models

    NARCIS (Netherlands)

    Dongen, van B.F.; Dijkman, R.M.; Mendling, J.

    2007-01-01

    Quality aspects become increasingly important when business process modeling is used in a large-scale enterprise setting. In order to facilitate a storage without redundancy and an efficient retrieval of relevant process models in model databases it is required to develop a theoretical understanding

  8. Steady-State Process Modelling

    DEFF Research Database (Denmark)

    Cameron, Ian; Gani, Rafiqul

    2011-01-01

    illustrate the “equation oriented” approach as well as the “sequential modular” approach to solving complex flowsheets for steady state applications. The applications include the Williams-Otto plant, the hydrodealkylation (HDA) of toluene, conversion of ethylene to ethanol and a bio-ethanol process....

  9. Analytical evaluation of energy efficiency potential enhancement of heat-generating units by flow variation in the boiler circuit

    Directory of Open Access Journals (Sweden)

    Artamonov Pavel A.

    2017-01-01

    Full Text Available Three-dimensional models of the most common boiler schemes are developed and the hydraulic characteristic of each scheme is built. The calculation results of the main technical and economic indicators of the schemes are done. They are energy, metal consumption, capital costs and operating costs. According to the results of the analysis, there is a technical solution to reduce the energy consumption of the boiler circuit pumping equipment. The complex evaluation of the options in the context of the boiler manufacturer and operation is made, the investment attractiveness is calculated.

  10. The impact of working memory and the "process of process modelling" on model quality: Investigating experienced versus inexperienced modellers

    DEFF Research Database (Denmark)

    Martini, Markus; Pinggera, Jakob; Neurauter, Manuel

    2016-01-01

    of reconciliation phases was positively related to PM quality in experienced modellers. Our research reveals central cognitive mechanisms in process modelling and has potential practical implications for the development of modelling software and teaching the craft of process modelling....... the role of cognitive processes as well as modelling processes in creating a PM in experienced and inexperienced modellers. Specifically, two working memory (WM) functions (holding and processing of information and relational integration) and three process of process modelling phases (comprehension...

  11. 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...

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

    Science.gov (United States)

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

    2010-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1992-03-01

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

  14. Styles in business process modeling: an exploration and a model

    NARCIS (Netherlands)

    Pinggera, J.; Soffer, P.; Fahland, D.; Weidlich, M.; Zugal, S.; Weber, B.; Reijers, H.A.; Mendling, J.

    2015-01-01

    Business process models are an important means to design, analyze, implement, and control business processes. As with every type of conceptual model, a business process model has to meet certain syntactic, semantic, and pragmatic quality requirements to be of value. For many years, such quality

  15. Process generalization in conceptual models

    NARCIS (Netherlands)

    Wieringa, Roelf J.

    In conceptual modeling, the universe of discourse (UoD) is divided into classes which have a taxonomic structure. The classes are usually defined in terms of attributes (all objects in a class share attribute names) and possibly of events. For enmple, the class of employees is the set of objects to

  16. Numerical modelling of reflood processes

    International Nuclear Information System (INIS)

    Glynn, D.R.; Rhodes, N.; Tatchell, D.G.

    1983-01-01

    The use of a detailed computer model to investigate the effects of grid size and the choice of wall-to-fluid heat-transfer correlations on the predictions obtained for reflooding of a vertical heated channel is described. The model employs equations for the momentum and enthalpy of vapour and liquid and hence accounts for both thermal non-equilibrium and slip between the phases. Empirical correlations are used to calculate interphase and wall-to-fluid friction and heat-transfer as functions of flow regime and local conditions. The empirical formulae have remained fixed with the exception of the wall-to-fluid heat-transfer correlations. These have been varied according to the practices adopted in other computer codes used to model reflood, namely REFLUX, RELAP and TRAC. Calculations have been performed to predict the CSNI standard problem number 7, and the results are compared with experiment. It is shown that the results are substantially grid-independent, and that the choice of correlation has a significant influence on the general flow behaviour, the rate of quenching and on the maximum cladding temperature predicted by the model. It is concluded that good predictions of reflooding rates can be obtained with particular correlation sets. (author)

  17. Evaluation of thermal overload in boiler operators.

    Science.gov (United States)

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

    2012-01-01

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

  18. Branching process models of cancer

    CERN Document Server

    Durrett, Richard

    2015-01-01

    This volume develops results on continuous time branching processes and applies them to study rate of tumor growth, extending classic work on the Luria-Delbruck distribution. As a consequence, the authors calculate the probability that mutations that confer resistance to treatment are present at detection and quantify the extent of tumor heterogeneity. As applications, the authors evaluate ovarian cancer screening strategies and give rigorous proofs for results of Heano and Michor concerning tumor metastasis. These notes should be accessible to students who are familiar with Poisson processes and continuous time. Richard Durrett is mathematics professor at Duke University, USA. He is the author of 8 books, over 200 journal articles, and has supervised more than 40 Ph.D. students. Most of his current research concerns the applications of probability to biology: ecology, genetics, and most recently cancer.

  19. Decoupled numerical simulation of a solid fuel fired retort boiler

    International Nuclear Information System (INIS)

    Ryfa, Arkadiusz; Buczynski, Rafal; Chabinski, Michal; Szlek, Andrzej; Bialecki, Ryszard A.

    2014-01-01

    The paper deals with numerical simulation of the retort boiler fired with solid fuel. Such constructions are very popular for heating systems and their development is mostly based on the designer experience. The simulations have been done in ANSYS/Fluent package and involved two numerical models. The former deals with a fixed-bed combustion of the solid fuel and free-board gas combustion. Solid fuel combustion is based on the coal kinetic parameters. This model encompasses chemical reactions, radiative heat transfer and turbulence. Coal properties have been defined with user defined functions. The latter model describes flow of water inside a water jacked that surrounds the combustion chamber and flue gas ducts. The novelty of the proposed approach is separating of the combustion simulation from the water flow. Such approach allows for reducing the number of degrees of freedom and thus lowering the necessary numerical effort. Decoupling combustion from water flow requires defining interface boundary condition. As this boundary condition is unknown it is adjusted iteratively. The results of the numerical simulation have been successfully validated against measurement data. - Highlights: • New decoupled modelling of small scale boiler is proposed. • Fixed-bed combustion model based on kinetic parameters is introduced. • Decoupling reduced the complexity of the model and computational time. • Simple and computationally inexpensive coupling algorithm is proposed. • Model is successfully validated against measurements

  20. Plasma Processing of Model Residential Solid Waste

    Science.gov (United States)

    Messerle, V. E.; Mossé, A. L.; Nikonchuk, A. N.; Ustimenko, A. B.; Baimuldin, R. V.

    2017-09-01

    The authors have tested the technology of processing of model residential solid waste. They have developed and created a pilot plasma unit based on a plasma chamber incinerator. The waste processing technology has been tested and prepared for commercialization.