DOCSLIB.ORG

An Integrated Study of Flue Gas Flow and Superheating Process in Recovery Boiler Using Computational Fluid Dynamics and 1D-Process Modelling

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
An Integrated Study of Flue Gas Flow and Superheating Process in Recovery Boiler Using Computational Fluid Dynamics and 1D-Process Modelling An Integrated Study of Flue Gas Flow and Superheating Process in Recovery Boiler using Computational Fluid Dynamics and 1D-Process Modelling Kunal Kumar Andritz Oy, Viljami Maakala Andritz Oy and Ville Vuorinen Aalto University ABSTRACT Superheaters are the last heat exchangers on the steam side in recovery boilers. They are typically made of expensive materials due to the high steam temperature and risks associated with ash-induced corrosion. Therefore, detailed knowledge about the steam properties and material temperature distribution is essential for improving the energy efficiency, cost efficiency and safety of recovery boilers. In this work, for the first time, a comprehensive 1D-process model (1D-PM) for superheated steam cycle is developed and linked with a full-scale 3D CFD (computational fluid dynamics) model of the superheater region flue gas flow. The results indicate that first; the geometries of headers and superheater platens affect platen-wise steam distribution. Second, the CFD solution of the 3D flue gas flow field and platen heat flux distribution coupled with the 1D-PM affect the generated superheated steam properties and material temperature distribution. These new observations clearly demonstrate the value of the present integrated CFD/1D-PM modelling approach. It is advantageous for trouble shooting, optimizing the performance of superheaters and selecting their design margins for the future. The developed integrated modelling approach could also be relevant for other large-scale energy production units such as biomass-fired boilers. 1 INTRODUCTION Recovery boilers are used to combust black liquor for chemical recovery and producing high-pressure superheated steam. The generated steam is utilized for self-sustainable pulp mill operations and electricity generation. For instance, in Finland in 2017, 8.1% of total electricity was generated with black liquor combustion in recovery boilers [1]. Global production of chemical wood pulp has been forecasted to increase annually by 1% [2]. Tran et al. [3] noted that approximately 1.5 kg of black liquor dry solids (BLDS) are produced per 1.0 kg of chemical wood pulp production and around 3.5 kg of superheated steam is generated per 1.0 kg of BLDS combustion in recovery boilers. Hence, black liquor is a vital biomass based renewable energy source from future perspective. Over recent years, the global interest for carbon neutral energy production has been continuously increasing to mitigate the climate change. Simultaneously, the conventional role of recovery boilers as chemical recovery units is shifting towards renewable energy production [4]. In addition, the average capacity of recovery boilers has been increasing. The current largest capacity of a recovery boiler is 12000 tds/d and even larger recovery boilers have been planned. Therefore, it is essential to develop new computational models for such large boilers to understand their heat transfer phenomena in detail, and to improve their contribution for renewable energy production. The superheater region in a recovery boiler is the focus of this work. The superheaters are single-phase heat exchangers. They are used to convert saturated steam into superheated steam by capturing heat from hot flue gas (≈ 30% of total). They are the last and one of the largest heat transfer surfaces in a recovery boiler before the steam turbine. Thence, the optimal performance of superheaters, including higher quality superheated steam production and reduction in material issues such as corrosion, is essential for efficient and safe recovery boiler power plant operation. Previously, detailed studies have been performed for coal-fired boilers and bubbling fluidized bed (BFB) boilers to analyze the heat transfer sections including superheaters, and to study the steam generation process using integrated CFD/1D-PM modelling approaches. In integrated CFD/1D-PM simulations, a flue gas side 3D CFD (computational fluid dynamics) model is coupled with a 1D-PM (1D-process model) of water-steam side. It is beneficial to utilize the 1D-PM for large and complex flows in the steam cycle, which are not feasible to solve with standalone CFD modelling. The reasons are large computational cost, time and availability of computational resources. 1 Edge et al. [5] studied the steam generation process in a 500 MWe natural circulating coal-fired boiler using integrated CFD/1D-PM simulations. Schuhbauer et al. [6], Chen et al. [7] and Park et al. [8] performed integrated CFD/1D-PM simulations, and studied the heat transfer between hot flue gas and water-steam cycle in coal-fired boilers. Yang et al. [9] also carried out integrated simulations to analyze the temperature distribution on furnace walls and the heating process of supercritical- carbon dioxide (S-CO) in a conceptual higher efficiency (≥50%) coal-fired boiler. Moreover, Hovi et al. [10] carried out transient integrated simulations, and investigated the effects of rapid load change situations on flue gas temperature, heat transfer and pollutant formation in a BFB boiler. Hence, it is seen that integrated modelling approach is state-of-the-art for coal-fired boilers and BFB boilers. However, in these previous studies the 1D-process models have mainly focused on the water circulation process, and the models utilized for the heat transfer sections have been simplified and based on porous media method. The porous media method does not provide an accurate solution for the flow field and material temperature distribution for the tube bundles in the heat transfer section. Therefore, in the present work, each superheater platen is modeled separately and comprehensively on both the CFD side and the 1D-PM side, which has not been done previously to the authors’ knowledge. In context of recovery boilers, the flue gas flow field and heat transfer in superheater region have been studied previously using standalone CFD simulations. Saviharju et al. [11] analyzed the flow field and temperature distribution in the upper furnace for two recovery boilers. Leppänen et al. [12, 13, 14, 15] studied deposit formation in recovery boilers and compared the results with experimental data. Maakala et al. [16] used surrogate-based analysis with CFD to optimize the heat transfer in superheater region. Maakala et al. [17] developed a detailed 3D CFD model for superheater region, and obtained a detailed 3D solution for flue gas flow field and heat flux distribution to superheater platens. However, the effects of flue gas side on the steam cycle and vice versa have not been well explored in the superheater region of recovery boilers, even though recovery boilers contribute around 25% of global industrial biomass based energy production [18]. In addition, there are few previous studies available where full-scale 3D CFD modelling approach has been adopted for recovery boiler simulations. Therefore, the main objective of this paper is to improve the understanding about heat transfer between hot flue gas and superheated steam cycle. The study includes the effects of 3D flue gas flow field in superheater region on heat flux distribution, steam distribution and material temperature distribution among the superheater platens. For this purpose, a full-scale 3D CFD model of superheater region is coupled with a detailed 1D-PM and integrated CFD/1D- PM simulations are performed. The developed 1D-PM is validated with reference data. This integrated CFD/1D-PM modelling approach is the novelty of this work. 2 METHODS AND MODELS 2.1 Description of the Case Figure 1-a shows the domain of the recovery boiler CFD model. The superheater region is marked in the figure by a rectangular box. The capacity of the recovery boiler is 1000 tds/d. The combustion of black liquor is assumed to be completed before the flue gas reaches the superheater region. Therefore, the furnace is not considered in this work. Table 1 shows the main operating parameters of the boiler. The reference data for recovery boiler was obtained at approximately 80% of its total capacity. It comprises of mass and energy balance calculations, and data from a measurement campaign. The model inlet is located between the tertiary air supply level and nose arch. This is done to assure that the tertiary air supply has minimum effect on the flue gas flow and the flow field is steady when flue gas reaches the superheater region. Similarly, the outlet is located far away from the superheater region to prevent the impact of outlet boundary conditions to the numerical solution of superheater region. The boiler walls, rear wall screen and boiler bank are evaporating surfaces. They are used to convert saturated water into saturated steam at almost a constant saturation temperature. The chosen recovery boiler has four stages of superheating (SH) including SH1A, SH1B, SH2, SH3 and SH4. The first stage superheaters (SH1A and SH1B) are counter-current superheaters according to the flue gas flow direction. The other superheaters are co-current heat 2 exchangers. Each superheater is made of 21 platens that are equally spaced across the width of the boiler. In reality, each platen has in-line, thin, seamless and tightly spaced tubes that carry steam inside. In this work, the superheater platens are considered as flat plates and linked with the 1D-PM on the steam side. Similarly, the boiler walls are modelled as flat surfaces instead of tightly fitted heated riser tubes. The boiler bank is modelled as a porous medium with calculated porosity, inertial loss coefficients and heat sink values. These simplifications are used to reduce the calculation time and complexity of the integrated CFD/1D-PM simulations. a b Figure 1: a) A two dimensional view of the recovery boiler geometry. 1) furnace (not considered), 2) inlet, 3-7) boiler walls, 8) nose level, 9) rear wall screen, 10) boiler bank, 11) outlet, 12) steam inlet and 13) superheated steam to the steam turbine. The boiler walls 3 and 4 are the side walls. The superheater region is represented with a rectangular box.
Load more

Recommended publications
  • Product Index for Print
    Bull: ABS-CEJS-24SC-01 March 2009 AUXILIARY BOILER SYSTEMS ELECTRICELECTRIC STEAMSTEAM PACKAGEDPACKAGED Power generation projects require an For maximum flexibility of operation, quick auxiliary boiler system to provide steam on response, precise of control and avoidance start-up, during maintenance shut-downs, of environmental consequences, the electric for steam turbine gland systems, etc. solution is the best choice. For the past 45 years ACME-AEP has Pressure Vessels are built to ASME Code or manufactured the key components of auxiliary EU Pressure Vessels Directive. boiler systems, namely boilers, superheaters, Electrical Standards meet CSA or UL or CE. secondary pressure vessels and associated control systems. Quality control is according to ISO 9001 (2000). The Acme ABS Packages are up to date solutions to current problems. 1 Ref: 19-092038 P & I DIAGRAM FOR CEJS HIGH VOLTAGE ELECTRODE BOILER WITH 2 CIRCULATION PUMPS The two diagrams shown are built around the key boiler component availability: CEJS High Voltage Electrode Steam Boiler 24 SC Immersion Element type Boiler Power: 5 MW to 52 MW Power: 600 kW to 3.5 MW Voltages: 6.9 kV to 25 kV, 3 phase, 4 wires Voltages: 380 V, 400 V, 415 V, 480 V, 600 V. 3 phase, 50/60Hz Design Pressure: 150 PSI to 500 PSI Design Pressure: 100 PSI to 600 PSI Operating Pressure: 105 PSI to 450 PSI Operating Pressure: 30 PSI to 540 PSI VERTICAL BOILER HORIZONTAL or VERTICAL BOILER Metal: Carbon steel Metal: Carbon steel or Stainless Steel Heating Elements: Flanged, Incoloy 800 2 Ref: 23-092044 ELECTRIC ELEMENT BOILER - SUPERHEATER PACKAGE PIPING DIAGRAM The two diagrams shown are slightly different but complement each other.
    [Show full text]
  • Advanced Organic Vapor Cycles for Improving Thermal Conversion Efficiency in Renewable Energy Systems by Tony Ho a Dissertation
    Advanced Organic Vapor Cycles for Improving Thermal Conversion Efficiency in Renewable Energy Systems By Tony Ho A dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Engineering – Mechanical Engineering in the Graduate Division of the University of California, Berkeley Committee in charge: Professor Ralph Greif, Co-Chair Professor Samuel S. Mao, Co-Chair Professor Van P. Carey Professor Per F. Peterson Spring 2012 Abstract Advanced Organic Vapor Cycles for Improving Thermal Conversion Efficiency in Renewable Energy Systems by Tony Ho Doctor of Philosophy in Mechanical Engineering University of California, Berkeley Professor Ralph Greif, Co-Chair Professor Samuel S. Mao, Co-Chair The Organic Flash Cycle (OFC) is proposed as a vapor power cycle that could potentially increase power generation and improve the utilization efficiency of renewable energy and waste heat recovery systems. A brief review of current advanced vapor power cycles including the Organic Rankine Cycle (ORC), the zeotropic Rankine cycle, the Kalina cycle, the transcritical cycle, and the trilateral flash cycle is presented. The premise and motivation for the OFC concept is that essentially by improving temperature matching to the energy reservoir stream during heat addition to the power cycle, less irreversibilities are generated and more power can be produced from a given finite thermal energy reservoir. In this study, modern equations of state explicit in Helmholtz energy such as the BACKONE equations, multi-parameter Span- Wagner equations, and the equations compiled in NIST REFPROP 8.0 were used to accurately determine thermodynamic property data for the working fluids considered. Though these equations of state tend to be significantly more complex than cubic equations both in form and computational schemes, modern Helmholtz equations provide much higher accuracy in the high pressure regions, liquid regions, and two-phase regions and also can be extended to accurately describe complex polar fluids.
    [Show full text]
  • Parallel-Powered Hybrid Cycle with Superheating “Partially” by Gas
    Parallel-Powered Hybrid Cycle with Superheating “Partially” by Gas Turbine Exhaust Milad Ghasemi, Hassan Hammodi, Homan Moosavi Sigaroodi ETA800 Final Thesis Project Division of Heat and Power Technology Department of Energy Technology Royal Institute of Technology Stockholm, Sweden [This page is left intentionally blank for the purposes of printing] Abstract It is of great importance to acquire methods that has a sustainable solution for treatment and disposal of municipal solid waste (MSW). The volumes are constantly increasing and improper waste management, like open dumping and landfilling, causes environmental impacts such as groundwater contamination and greenhouse gas emissions. The rationalization of developing a sustainable solution implies in an improved way of utilizing waste resources as an energy source with highest possible efficiency. MSW incineration is by far the best available way to dispose the waste. One drawback of conventional MSW incineration plants is that when the energy recovery occurs in the steam power cycle configuration, the reachable efficiency is limited due to steam parameters. The corrosive problem limits the temperature of the superheated steam from the boiler which lowers the efficiency of the system. A suitable and relatively cheap option for improving the efficiency of the steam power cycle is the implementation of a hybrid dual-fuel cycle. This paper aims to assess the integration of an MSW incineration with a high quality fuel conversion device, in this case natural gas (NG) combustion cycle, in a hybrid cycle. The aforementioned hybrid dual-fuel configuration combines a gas turbine topping cycle (TC) and a steam turbine bottoming cycle (BC). The TC utilizes the high quality fuel NG, while the BC uses the lower quality fuel, MSW, and reaches a total power output of 50 MW.
    [Show full text]
  • Physics, Chapter 17: the Phases of Matter
    University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Robert Katz Publications Research Papers in Physics and Astronomy 1-1958 Physics, Chapter 17: The Phases of Matter Henry Semat City College of New York Robert Katz University of Nebraska-Lincoln, [email protected] Follow this and additional works at: https://digitalcommons.unl.edu/physicskatz Part of the Physics Commons Semat, Henry and Katz, Robert, "Physics, Chapter 17: The Phases of Matter" (1958). Robert Katz Publications. 165. https://digitalcommons.unl.edu/physicskatz/165 This Article is brought to you for free and open access by the Research Papers in Physics and Astronomy at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Robert Katz Publications by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. 17 The Phases of Matter 17-1 Phases of a Substance A substance which has a definite chemical composition can exist in one or more phases, such as the vapor phase, the liquid phase, or the solid phase. When two or more such phases are in equilibrium at any given temperature and pressure, there are always surfaces of separation between the two phases. In the solid phase a pure substance generally exhibits a well-defined crystal structure in which the atoms or molecules of the substance are arranged in a repetitive lattice. Many substances are known to exist in several different solid phases at different conditions of temperature and pressure. These solid phases differ in their crystal structure. Thus ice is known to have six different solid phases, while sulphur has four different solid phases.
    [Show full text]
  • QUIZ: Boiler System Components
    9707 Key West Avenue, Suite 100 Rockville, MD 20850 Phone: 301-740-1421 Fax: 301-990-9771 E-Mail: [email protected] Part of the recertification process is to obtain Continuing Education Units (CEUs). One way to do that is to review a technical article and complete a short quiz. Scoring an 80% or better will grant you 0.5 CEUs. You need 25 CEUs over a 5-year period to be recertified. The quiz and article are posted below. Completed tests can be faxed (301-990-9771) or mailed (9707 Key West Avenue, Suite 100, Rockville, MD 20850) to AWT. Quizzes will be scored within 2 weeks of their receipt and you will be notified of the results. Name: ______________________________________________ Company: ___________________________________________ Address: ____________________________________________ City: ______________________ State: _____ Zip: ________ Phone: ______________________ Fax: __________________ E-mail: _____________________________________________ Boiler Systems – Boiler Components By Irvin J. Cotton, Arthur Freedman Associates, Inc. and Orin Hollander, Holland Technologies, Inc. This is part two of a three-part series on boilers. In part one, the authors discussed boiler design and classification. Part two will discuss boiler components, and part three will describe the various chemistries used in boiler water treatment. Boiler Components The main components in a boiler system are the boiler feedwater heaters, deaerator, boiler, feed pump, economizer, boiler, superheater, attemperator, steam system, condenser and the condensate pump. In addition there are sets of controls to monitor water and steam flow, fuel flow, airflow and chemical treatment additions. Water sample points may exist at a number of places. Most typically the condensate, deaerator outlet, feedwater (often the economizer inlet), boiler, saturated steam and superheated steam will have sample points.
    [Show full text]
  • Thermodynamics of Air-Vapour Mixtures Module A
    roJuclear Reactor Containment Design Chapter 4: Thermodynamics ofAir-Vapour Mixtures Dr. Johanna Daams page 4A - 1 Module A: Introduction to Modelling CHAPTER 4: THERMODYNAMICS OF AIR-VAPOUR MIXTURES MODULE A: INTRODUCTION TO MODELLING MODULE OBJECTIVES: At the end of this module, you will be able to describe: 1. The three types of modelling, required for nuclear stations 2. The differences between safety code, training simulator code and engineering code ,... --, Vuclear Reector Conte/nment Design Chapter 4: Thermodynamics ofAir-Vapour Mixtures ". Johanna Daams page 4A-2 Module A: Introduction to Modelling 1.0 TYPES OF MODELLING CODE n the discussion of mathematical modelling of containment that follows, I will often say that certain !pproxlmatlons are allowable for simple simulations, and that safety analysis require more elaborate :alculations. Must therefore understand requirements for different types of simulation. 1.1 Simulation for engineering (design and post-construction design changes): • Purpose: Initially confirm system is within design parameters • limited scope - only parts of plant, few scenarios - and detail; • Simplified representation of overall plant or of a system to design feedback loops 1.2 Simulation for safety analysis: • Purpose: confirm that the nuclear station's design and operation during normal and emergency conditions will not lead to unacceptable excursions in physical parameters leading to equipment failure and risk to the public. Necessary to license plant design and operating mode. • Scope: all situations that may cause unsafe conditions. All systems that may cause such conditions. • Very complex representation of components and physical processes that could lead to public risk • Multiple independent programs for different systems, e.g.
    [Show full text]
  • PATENT SPECIFICATION <N) 1421907
    PATENT SPECIFICATION <n) 1421907 (21) Application No. 39315/72 (22) Filed 23 Aug. 1972 (19) O ON (23) Complete Specification filed 13 Aug. 1973 (44) Complete Specification published 21 Jan. 1976 H (51) INT. CL.8 F22G 5/18 F22B 1/06 (52) Index at acceptance H F4A 8C Gil G19 G20 (72) Inventors: ANTHONY RANDLE LUNT and THOMAS DAVID ROBERTS (54) STEAM GENERATING PLANTS (71) We, UNITED KINGDOM ATOMIC superheater 2 for heat exchange with liquid ENERGY AUTHORITY LONDON, a British sodium. The liquid sodium is supplied from a Authority do hereby declare the invention, sodium cooled nuclear reactor which also is 50 for which we pray that a patent may be not shown as it forms no part of the present 5 grantedjjto us, and the method by which it is to invention. Between the steam drum 1 and the be performed, to be particularly described superheater 2 there is an injector 3 which is in and by the following statement:— connected by a branch line 4 to the outlet 5 This invention relates to steam generating of the superheater. The outlet 5 is also con- 55 plants. nected to a turbine stop valve (not shown). 10 In one known construction of steam gen- The branch line includes a control valve 6. erating plant wet steam is separated from the Referring now to Figure 2 the injector 3 liquid phase in a steam drum and the wet comprises a housing 7 having a nozzle 8 and steam is fed to a superheater constructed from a diffuser 9. The nozzle 8 is connected to the 60 stainless steel and through which liquid metal steam drum 1 whilst the diffuser 9 is con- 15 is passed in heat exchange with the steam.
    [Show full text]
  • The Case for the AMERICAN Steam Locomotive
    • raIns. AUGUST 1967 • 60, T .. ... ----------------- ' f!,' lIelllelllh~'1' jhis al'jkle ill IIl'cf'lIIh~'1' I!'f;f; TIC,\INS? Xow "'I ('xllel'j ('Ollles THE CASE fOR THE fRENCH STEAM"' LOCOMOTIVE iOl'jh with •.. The case for the AMERICAN steam locomotive 21 Avgus! 1967 - VERNON l. SMITH illVllrolion AUTHOR'S COllECTION OR AS NOTED 1 IN htl ''The Case lor the F~nch trains to be bandied - In America background r($ultcd In fine, ('COnomi- Steam Loc:omoltv(''' in Decem· th~ arc !ugh and harsh. 1::al handhna; of compound engines, her 1966 TRAINS, author R. K. E ... tVl!> (3) MllK:ellancous conditIons - thc Many of the later (our-cylindcI' en_ stated, ", .. The fact ,'emains unques­ labol' market, the workIng clearances gines have the two r(l8ch I'ods cvn­ ti oned that nowhere in the world W3$ (loading gau,ge), the maIntenance ncctcd or 11ll1ned togcther to avoid the art of Sl~ locomotivt' design praclLcH, and the 1~'omoIlH: availa­ ImpI'opcr dIvision of the work by the developed as far and 1.$ clOSt' to per_ bility and utilization required. englneman b<>tween the hil1;h- and ft.oction as In France," MI'. Evans in his arucle Jit>okl> of lov.·-plcssul·c syste.ns, This suggeslS I question the claim put forth by compounding and mamtenance, draw­ that the labol market may be chonging Mr. Evans, because It 111 not supported bu horsepow(>r, fuel et.'(lnomy, valve Il\ France and that less refined loco­ by data and performance records gears. improved (ront ends, enlarged mouve dnving is taking place, And It gother(X{ during !.he high Iide of tteam and exhaust pa...sages, riding means that some of the original ('C;'01l- American locomolh,c design qualities and speed, and bOIler blow_ 01111(-'$ ar1! not beint, obtained.
    [Show full text]
  • Numerical Investigation of Superheater Tube Failure
    This paper is part of the Proceedings of the 14th International Conference on Simulation and Experiments in Heat Transfer and its Applications (HT 2016) www.witconferences.com Numerical investigation of superheater tube failure H. H. Al-Kayiem & T. M. B. Albarody Mechanical Engineering Department, Universiti Teknologi PETRONAS, Perak, Malaysia Abstract Industrial superheaters in petrochemical plants possess leakages due to failure in many areas. This paper presents the results of investigations into identifying the failure causes. The investigations were carried out by simulating the heating process of a superheater. The simulation was carried out numerically using ANSYS mechanical commercial software. The simulation results indicated that the superheater tubes were subjected to direct radiation heat transfer as well as flame violence. The leakage spots were formed due to cracks in the material mainly at the joint points between the tubes and the header. It was also realized that the welding at the connection areas of the pipes and the header had weakened the material and formed low thermal resistance spots which could not stand the 510°C temperature and consequently, it had either melted or cracked. Keywords: boiler, superheater, thermal wave, thermal fatigue, thermal stress. 1 Introduction The basic failure mechanism, in the piping process, is fatigue due to vibration and/or thermal stresses caused by internal and/or external flows in pipes, junctions, and bends. When high temperature exists in the process, the possibility of thermal fatigue increases the possibilities of piping failure. In the industrial practice, such problem is commonly associated with boilers, risers, and pipes subjected to intermittent internal flow and periodic heat impact from internal or external sources.
    [Show full text]
  • Conventional Steam
    DECEMBER 2019 Application Solutions Guide CONVENTIONAL STEAM Experience In Motion 1 Application Solutions Guide — The Global Combined Cycle Landscape TABLE OF CONTENTS THE GLOBAL CONVENTIONAL STEAM POWER FLOWSERVE PRODUCTS IN CONVENTIONAL PLANT LANDSCAPE . 3 STEAM POWER . 16 A Closer Look at Conventional Steam Conventional Steam Applications Power Technology . 5 Overview . 16 Basics . 5 Pumps for Conventional Steam Plants . 18 Plant Configurations and Sizes . 7 Valves for Conventional Steam Plants . 24 Flue Gas Desulfurization (FGD) . 8 Actuators for Conventional Steam Plants . 30 Conventional Steam Project Models . 11 Seals for Conventional Power Plants . 31 Seals for Wet Limestone Flue Gas THE CONVENTIONAL STEAM POWER- Desulfurization . 33 FLOWSERVE INTERFACE . 13 Business Impact and Focus Areas . 13 COMMUNICATING OUR VALUE . 34 The Big Picture . 13 Innovative Ways Flowserve Addresses The Flowserve Fit in Conventional Customer Challenges . 34 Steam Power . 13 APPENDIX . 35 PRODUCTS FOR STEAM POWER — Flowserve Value Proposition in Conventional Steam . 35 AT A GLANCE . 14 Sub-critical Versus Supercritical Pumps . 14 Power Plant . 36 Valves . 14 Reheat . 37 Seals . 14 Terminology . 38 Estimated Values by Plant Size . 15 Acronyms . 39 2 Application Solutions Guide — Conventional Steam THE GLOBAL CONVENTIONAL STEAM POWER PLANT LANDSCAPE Thermal power generation involves the conversion Combined cycle plants have become the preferred of heat energy into electric power. Fossil fuel power technology for gas-fired power generation for several plants as well as nuclear, biomass, geothermal reasons. The USC plant takes 40 to 50 months to and concentrated solar power (CSP) plants are all build; a combined cycle plant can be built in 20 to examples of thermal power generation.
    [Show full text]
  • Thermodynamic Data
    Thermodynamic Data It is not possible to know the absolute value of U ˆ or H ˆ for a pure substance, but you can determine the change in U ˆ ( U ˆ ) or Hˆ ( Hˆ ) corresponding to a specified change of state (temperature, pressure, and phase). The change is actually often what we want to know. A common practice is to arbitrarily designate a reference state for a substance at which U ˆ and H ˆ are arbitrarily set to be equal to zero, and then tabulate U ˆ and/or H ˆ for the substance relative to the reference state. For example, ˆ CO (g, 0C, 1 atm) CO (g,100C, 1 atm): HCO 2919 J/mol ˆ ˆ reference state HCO HCO 0 2919 J/mol We say: “The specific enthalpy of CO at 100C and 1 atm relative to CO at 0C and 1 atm is 2919 J/mol”. CHEE 221 1 Reference States and State Properties Most (all?) enthalpy tables report the reference states (T, P and State) on which the values of H ˆ are based; however, it is not necessary to know the reference state to calculate H (change in enthalpy) for the transition from one state to another. ˆ ˆ –H from state 1 to state 2 equals H 2 H 1 regardless of the reference state upon which ˆ and ˆ were based H1 H 2 – Caution: If you use different tables, you must make sure they have the same reference state This result is a consequence of the fact that H ˆ (and U ˆ ) are state properties, that is, their values depend only on the state of the species (temperature, pressure, state) and not on how the species reached its state.
    [Show full text]
  • Watertube Boilers
    Watertube Boilers Learning Outcome When you complete this module you will be able to: Describe various watertube boiler designs, including large generating units. Learning Objectives Here is what you will be able to do when you complete each objective: 1. Describe early designs and construction of watertube boilers. 2. Sketch and describe the design and construction of packaged watertube boilers. 3. Describe the design, construction, and components of large scale steam generating units. 1 BLRS 6016 INTRODUCTION The watertube boiler differs from the firetube design in that the tubes contain water rather than combustion gases. In the watertube boiler, the combustion gases travel over the outside surfaces of the tubes and transfer their heat to the water within the tubes. WATERTUBE BOILERS Longitudinal Straight Tube Boilers Fig. 1 illustrates one of the earliest straight tube boilers. The drum runs longitudinally in relation to the tubes. The straight inclined tubes run between vertical headers at the front and rear of the drum; these headers are connected to the drum at their top ends. The combustion gases make three passes across the tubes as indicated by the arrows in Fig. 1. AL_4_0_4.mov A AL4_fig1.gif Figure 1 Straight Tube Design (Longitudinal) The water circulates from the water space of the drum down the rear header, up the inclined tubes (at an angle of 15° to the steam drum), to the front header, and then back up to the drum. 2 BLRS 6016 Figure 2 AL4_fig2.gif Babcock & Wilcox Boiler (1877) The early boiler shown in Fig. 2 had an elaborate setting.
    [Show full text]